View Full Version : Custom Gauges

02-22-2011, 09:03 PM
Hereís a little project of mine. Toyota purists turn away now.

When I bought my MR2 it already had a 4A-GZE swap and some other modifications including a Momo steering wheel. Having driven MR2ís of the same vintage with the stock wheel in place I have found that I prefer the smaller wheel. Unfortunately with where I sit in the car the top of the steering wheel obstructs the view of the top outer two gauges and the indicator and high beam lights. The two gauges it obstructs are the volt meter and the oil pressure gauges. The oil pressure gauge in the dash has never been accurate due to the fact that the person who did the swap left the 4A-GZE sender on the engine and it gives different values than the 4A-GE sender that was matched to the gauge. I solved this problem with an oil filter sandwich plate, a Lotek a pillar mount, and Autometer z-series oil pressure and oil temperature gauges.

I also had a boost gauge in an Autometer mount bolted to the steering column. At first I had an Autometer mechanical boost gauge in there, but it wasnít the best idea to run a boost/vacuum line from the engine, through the firewall, under the carpet, under the centre consol, through the dash to the column. This line did get pinched so I decided to put an electrical gauge in itís place. I ended up buying a second hand Greddy gauge. It looked fine during the day but at night it had an orange-red LED illumination that didnít match the rest of the gauges (stock black face white numbers with green illumination).


In that picture the dash is blue. That dash cracked and it now has a black on in its place.
Recently I started to work on my Megasquirt for the car (see link in my signature). This led me to thinking more about the overall car in more detail. The Lotek a-pillar pod is great, but it didnít quite have the fit that I wanted. I tried to heat it and bend it with a hot air gun, but this just led to the plastic warping. Not wanting to damage it further I put it back on the car (it mounted with two screws) and left it. Last summer I decided that I was unhappy with how it looked and that I would stop worrying about screwing it up and do something about it.

I grabbed a knife and a hacksaw and I cut the gauge pod up such that only the minimal amount of plastic to get it to hold the gauges remained. I then used some two part epoxy to glue it to the stock a-pillar. After it had dried I used some fibreglass reinforced body filler to blend it together. I then used some standard body filler to smooth out most of the imperfections (I say most because there were some that I didnít notice until after I had put it back on the car).

It was then a case of sand, fill, sand, fill until finally I hit it with some high build primer.

Again it was prime, sand, repeat. Once I had it finished I painted it with some Krylon satin black. It ended up looking gloss black.

I went back to the store and picked up some Krylon flat black. It matched the interior almost perfectly. I was pretty happy with the results. Sorry no pics of that.

One of the issues I had with my megasquirt install is that the output from the MS will not drive the tachometer directly. Itís not really a problem and if you look at my MS thread you will see how I solved it. However for simplicityís sake, it would be easier to use an aftermarket tach. I stated in the MS thread that I dislike aftermarket tachs because they look out of place in most cars, sometimes they even scream rice.

The synchros on the transmission are worn out and I found that it is cheaper and easier to convert a later model transmission from a front wheel drive car than it would be to get an MR2 transmission or rebuild mine. Since there are many 20V 4A-GE swaps happening in corollas there are several 20V transmissions not being used taking up space in garages. I was able to pick one of these up cheap.
Itís off of a silvertop so the only modification I need to make is to drill a hole for the selector shaft.
Another big issue that my car has is that it simply EATS speedometer cables. Since I bought the car it has chewed up the cable it came with, two junkyard cables, and two brand new ones. Since the new ones are $300+ with no warranty and full payment before ordering, this was getting expensive.
The new transmission I got didnít have a speedometer cable drive, but rather a vehicle speed sensor (VSS). I have a second engine for the car that came with a supercharged transmission with a VSS, but it was different (installed through the back instead of the top). However the plug was the same.

So this got me thinking, why should I keep sinking money into parts that are going to break when I have everything to convert to an electronic speedometer? Combine this with the fact that an aftermarket tachometer would be easier to drive and the stock volt meter, coolant temperature, and oil pressure gauges were pretty much useless with their simple H and L markings and the top two werenít even visible unless I moved my head and I found the motivation to make my own dash.

Here are the ďbeforeĒ pictures:

I started with a little bit of research. I wanted everything to look consistent, ie. be the same brand/style of gauge, and I wanted them to be useful. That means accuracy and actual numbers on the gauges (no more of this H and L nonsense).

I researched several companies that make gauges but in the end, for the price and availability I settled on Autometer. Autometer has many different styles of gauges with different faces and fonts and illuminations. I started by picking a speedometer. I would need electric and programmable. Living in Canada I would also need metric (Kph). I also wanted one that would fit in the dash (not 5Ē) so I settled on the 3 3/8Ē. This narrowed my selection to four gauges: Sport-Comp, Ultra-Lite, Carbon Fiber, and Phantom. The Phantom series has a white face and black ring. I didnít think this suited the car. The Carbon Fiber has a chrome ring which Iím really not a fan of. It came down to the Sport Comp with its black face and silver ring and the Ultra Lite with the silver face and silver ring. I checked out the other gauges that I would be using in both these series. According to the Autometer website the Pro Comp does not have full sweep electric gauges for most of the gauges I want. So I went with the Ultra Lite series.

The next decision I had to make was to determine what I wanted to monitor. I decided that I would have oil pressure and EGT in the a-pillar. On the dash I would have RPM, speed, fuel level, and Voltage. Over the centre console above the heater controls I would mount three more: Water temperature, Oil temperature, and a wideband air/fuel ratio for tuning the megasquirt. Finally I would put the boost gauge on the steering column.

I ordered five gauges right away: Tach, Speed, Boost, Volt, and Fuel level. Once they arrived I used my spare gauge cluster as a template and cut up many cardboard boxes for trial fittings (the paper/cardboard recycling bin is right outside my lab). I went through a couple of designs before I settled on having the two larger gauges in the middle with the smaller ones outside of these two at the bottom. I found that I could mount two more small ones above the two that I put in, but the steering wheel would make these hard to see.

I wanted it to fit like a stock gauge cluster so I started by taking apart my spare cluster and using that as a mount:
I dremelled this out such that only the frame remained:
And a cardboard test fit:
This cardboard test fit is pretty much my final design with LED holders for left and right indicators, high beam indicator, a low fuel warning indicator (car has senders in tank for a fuel gauge and a low fuel warning light stock). If you have a keen eye you may have noticed a knob in the upper left where the stock volt meter was. This is for dimming the lights on the new gauges as I will be using LEDs which canít be dimmed with the stock rheostat. Instead this controls a pulse width modulator for LED dimming.

After I was satisfied with the fit It was time to move onto building a more solid piece. I took my cardboard template and used it to cut a piece of hardboard to the right size:
I then cut holes in it for the gauges using a drill, jigsaw, and dremel and did another test fit:
The PWM is mounted using countersunk bolts that will be filled in.
Once all the holes are cut I removed the gauges and put it in place:

To keep it in place two part epoxy was used:

Once that was done I used some fibreglass to reinforce the edges and some fibreglass filler to smooth out the corners (sorry no pics). Then I hit it with some high build primer and found that I still had a lot of work ahead of me:

Making the thing one colour makes it easier to see the scratches and pin holes that need to be filled. Anyone who had done fibreglass or body work knows that a seemingly endless cycle of filing and sanding and priming and starting over is the next step. Of course I couldnít resist test fitting in between these stages:
I also had to make sure that it fit in the car:
And that there was enough space behind them for the wires:

Finally I was satisfied enough to paint it its final colour. The same black I used for the a-pillar:

Now that that was done I turned my attention to the boost gauge. Originally I had it in an Autometer mounting cup on the steering column. This worked but as you can see from my before picture way up near the beginning of this thread it stood rather high and blocked much of the speedometer. I decided that I would mount it as low as I could on the steering column. I started by heading to the hardware store with my boost gauge and finding a pipe that would fit it. The closest I found was a vacuflow coupling. I then sat in the car with the column cover and the coupler and cut a notch for the coupler to sit in and deep as I could before it hit the parts of the column underneath.

Once that was done I used epoxy to glue it to the column piece:
This wasnít deep enough to hold the gauge and cover the wiring behind it so I cut a second connector in half using my dremel. Wear safety glasses and a mask when doing this:
It too was glued in place:
I had to dremel the inside of the couplers a little because they were a little too tight for the boost gauge:

I then used some CA glue to glue some old t-shirt material over the connectors:
And the applied some fibreglass resin mixed with harder:
I should note that this should be done wearing a mask and preferably outdoors. As winter in Canada makes it almost impossible to fibreglass outdoors I used a fume hood in my lab at work (after hours and at lunch of course).

The part now has its shape, but it has no strength. So I cut up some fibreglass chop matt and applied that with resin:
In the last picture you can see that I also covered the hole for the cruise control lever that I no longer have.

I then test fit it against the gauge cluster I built. This is a worst case scenario as the column will never actually be this close to the gauges:
Looks good to me!

A little fibreglass reinforced body filler:
A little sanding:

Lather rinse repeat (many times).
A little high build primer:

And finally a test fit in the car:

Test fit with the new gauge cluster:

And again with the flat black paint:

Now there are a few little imperfections in it that bother me a bit, but Iím happy enough with it to put it in the car for now. I donít want this one little part to wear me down too much.

So now itís time to start looking at the wiring. I needed to test whether all the LEDs would work with twelve to fourteen volts (to make sure my resistor values were correct). So I used my bench power supply which I can vary the voltage with and tested.
Turning indicators:
Hi beams:
Low fuel:

The only LEDs I had at the time were the ďsuper brightĒ ones, so I upped the resistance a bit to cut the brightness down some. I donít want to be blinded by my dash at night.

I also tested that all the gauges powered up:
Many of the Ultra Lite gauges have peak memory and warnings built in. Where I can I would like to use them. The Voltmeter has one and I set it to warn at twelve volts or lower:
The reason for twelve or lower is that I no longer have a charge warning light. When the vehicle is running the voltage should be between thirteen and fourteen volts. If the vehicle is running and itís at twelve or lower the alternator isnít charging. So now I have a pseudo charge warning light. The boost meter has this function too, which could be used as an overboost warning. With my supercharger though I fully admit that itís just for show.

I also tested the night time illumination. In my lab there are some lights I canít turn off so I can only simulate low light conditions:
I am a little concerned that the two larger gauges might not have enough light for night time driving.

Once it was all confirmed to be working I made a wiring harness for it. It uses one twelve pin Molex plug to make it easy to install/remove. I also made the harness long enough that I can pull the gauge cluster out far enough to get in behind it really easily:

Yesterday was family day here in Canada so I went over to my parents and borrowed their heated garage. I used the wiring diagram for my car to wire up the mating Molex plug for my dash. After a few hours it was in and (for the most part) working.

Here is how it looked this morning right after I started my car:

All in all I am very pleased with the gauge placements. I can see all the gauges easily when driving and the turning indicator lights are finally visible. The fuel gauge seems a little funny. I am using a fully programmable on which requires that I calibrated it when the tank is empty, then fill the tank and calibrate it again. I had cut the fuel sender wire and brought it out under the dash for this purpose. I used power from the cigarette lighter to power the gauge and then calibrated it last time I filled up.

This morning on the way to work It would move from ľ tank to Ĺ tank depending on what the car was doing. The stock gauge had just over ľ tank on it when I removed it so for now I have to keep in mind that the lower reading is probably more accurate. I do not know what it will read when it gets down to the empty value I calibrated it for. I will have to wait and see. I also noticed that the boost gauge calibrates itself each time it gets turned on. I donít yet know if I have to let it go through its calibration before I start the car (what Iíve done so far, I like watching all the gauges calibrate themselves) or if I can start the car right away and it will remember the initial value. Iím sure Iíll find out through trial and error at some point. The tachometer seems to be much more reactive than the stock and I also suspect more accurate. I do have a few issues to sort though:

Problem: Speedometre doesnít work.
Reason: VSS not installed.
Solution: Find a way to remove stuck cable drive and install VSS. Last time my father and I tried to get it out we broke the threads for the cable off. Iím not sure how to get it out. Alternatively just wait until I swap the transmission.

Problem: Gas warning light is on all the time.
Reason: Sender for warning light is not a simple on/off as I assumed. When it is in its off state it has a resistance of 2.5Kohm (at least it does when there is ľ tank). This results in a small current that isnít enough to turn on the original bulb, but is enough to turn on an LED.
Solution: A slightly more complex circuit. By placing six volt zener diode in series with the LED and a resistor in parallel with the zener/LED circuit then connecting that to the switch in the tank will give me the control I need to turn this on only when the sender drops its resistance. Here is a diagram of that circuit:


It works by having the zener require six volts to allow current to flow through it. At the top of the circuit there is twelve volts. However the zener/LED part of the circuit isnít referenced to ground, it is referenced to the top of the fuel warning sender below the resistor in parallel. The voltage seen at the bottom of this resistor needs to be greater than eight volts when the sender isnít turning on the light. Eight volts comes from fourteen volts when the car is running and charging, minus the zener voltage of six. When the sender goes to ground to turn on the light the voltage after the resistor will drop significantly, and if the sender goes to ground like I first assumed, then this point will also be ground. This will make the zener ďseeĒ twelve volts, which is higher than six, so the LED will turn on. I will bring the wire for this out under the dash (probably tomorrow night) and connect it to a stock light bulb. When the light comes on I will measure the resistance for the sender and use that to calculate a value for my resistor.

Problem: High beam indicator isnít working.
Reason: Unknown at the moment. It worked when I first got the car in the stock cluster and eventually stopped working. I assumed that the bulb had burnt out. This has proven to be inaccurate. The wiring in the gauge cluster is fine and has been tested (see pic above). The wire from the carís harness isnít providing the twelve volts to turn it on.
Solution: Find the cause and fix it.

Problem: No idiot lights.
Reason: Did not build them into new dash.
Solution: I plan to move the useful ones to the centre of the dash above the heater controls. By useful I mean Charge, Low Brake Fluid, Hand Brake, and Cooling Fan Fault. Originally the low brake fluid and hand brake shared a light, but I would like to separate them. The two lights I will not be reconnecting are the Check Engine Light (Megasquirts doesn't use it) and Fasten Seat Belt Light. I feel naked in a moving car without a belt so its not like I'll forget.

Problem: Alarm will no longer allow me to remote start.
Reason: The alarm requires that the handbrake be on for remote start. All of the alarms wiring connections to the car (except for the high current start/ign/acc wires) are connected to a junction block in the kick panels. The circuit for the hand brake sits at twelve volts until the hand brake switch grounds it. Because the brake light has been removed from the dash this circuit is no longer complete.
Solution: Either wire up the hand brake sensor for the alarm straight to the brake or rewire a brake warning light. I will eventually be rewiring the light to the centre above the heater controls as already mentioned.

Problem: All the new gauges are using Autometerís blue LEDs for lighting. The smaller gauges look great however the larger two cannot be seen in no light conditions. They can be seen when driving under a street light and in low light conditions, but at eight thirty last night I couldnít see them on the dark streets.
Reason: The Autometer LEDís just arenít bright enough for the larger gauges.
Solution: Switch back to incandescent bulbs in with no colour covers. Not my ideal solution. I could also try and find other aftermarket LEDs that would fit in the Autometer socket. Or I could experiment with some super bright blue LEDs and make my own little cluster to match the brightness of the smaller gauges.

Problem: One gauge is lost. The stock cluster had six gauges in it, RPM, speed, voltage, oil pressure, fuel level, and coolant temperature. My gauge cluster has RPM, speed, voltage, fuel level, and I have oil pressure and oil temperature on the a-pillar.
Reason: I built the cluster to have all the gauges easily visible. This meant that I did not have space for any more gauges.
Solution: Mount a water temperature gauge elsewhere. My current vision is to have oil pressure and EGT in the a-pillar and water temp, oil temp, and A/F above the heater controls. This should give me all the gauges I desire.

Well that's my project as of now. I will update when I get things working and when I start on the centre consol bit. I have ordered the oil pressure gauge and it should be here sometime next week or so. I am hoping to change all the dash lights to blue. I know that this isn't that easy for everything. I may have to make my own clock using blue seven segment displays. And I may have to not have the lights for the defog switch and wipers hooked up at all. All to match the illumination of the radio....:lmfao:

Feedback welcome!

Oh, and I should thank ChrisD for letting me bounce ideas off him and support.


02-22-2011, 09:26 PM

02-22-2011, 09:59 PM
No prob! You've got some cool projects on the go.

Killer cockpit in this pic - love it.


02-22-2011, 10:14 PM
That is awesome.

Wanna make one for my car? :snicker:

02-22-2011, 11:01 PM
I liked the read, I like the product, I loved the pictures. Thank you for the post. That was quite detailed.

02-22-2011, 11:27 PM
Wow that turned out great looks a lot better and more useful. Nice work thanks for all the pictures

02-22-2011, 11:28 PM
Love the work. I will need to be trying something like this soon.

How much did the gauges set you back?

02-22-2011, 11:46 PM
Thanks for the comments guys!

How much did the gauges set you back?

Ugh... I'd rather not think about it lol. I have the receipts scattered a bit between the office and at home. The gauges I have in the car so far are about $700 worth. I have ordered the oil pressure which is about another $200.

Here is a list of the autometer gauges and their part numbers that I have:
Tachometer 4497
Speedometer 4487-M
Fuel Level 4310
Volt Meter 4383
Boost Meter 4377

Oil Pressure 4352

Waiting for a paycheck or two:
EGT 4343
Oil Temperature 4340
Water Temperature 4354

For the wideband I'm looking at the Innovate stuff. I'm leaning towards the XD-16. That will create another $300 hole in my wallet.

The prices at the local speed shop are comparible to the prices listed on JEGS, that and I don't have to pay shipping just so long as I'm patient about waiting for them to come in.


02-23-2011, 12:30 AM
The start up self calibration dance:
http://i150.photobucket.com/albums/s117/Berg9987/Dash/th_MOV20110222_001.jpg (http://s150.photobucket.com/albums/s117/Berg9987/Dash/?action=view&current=MOV20110222_001.mp4)

Shot this with my phone just before leaving work.


02-23-2011, 01:31 AM
A number of newer cars do that also.

And I kind of figured the gauges were pricey, was just hoping you had found a place with deals lol.

02-23-2011, 02:26 AM
Nice! Rock the Autometers!

02-23-2011, 03:08 AM
Very nice setup! I'm a bigger fan of Prosport gauges, but your setup looks great!

I'm loving the custom work.

02-24-2011, 01:40 AM
I think I might know why my high beam indicator isn't working.

I started by looking at the wiring schematic for my car found here: http://opc.mr2oc.com/online_parts_catalog/1988AW11_complete_wiring_diagrams4.pdf

All the headlight information can be found in Figures 1, 2, and 4. By the way, Figure 4 is what I used to wire my new gauges.

Anyway, by following those schematics it can be seen that unlike many domestic cars the dimmer switch to select between high beam and low beam switches the grounds of the filaments and not the power. It is wired up as such that when the lights are on power is supplied to a common pin on the three pin plugs for the headlights. One of the other pins is grounded through the dimmer switch for low beams. The wire that is connected to the dimmer switch that is being grounded for low beams is also connected to the high beam indicator bulb. The other side of the indicator bulb is connected to ground. So when the dimmer switch is in low beam both sides of the indicator bulb are grounded. When the dimmer switch is switched to hi beam the other pin of the three pin plug is grounded turning on the hi beams and the pin for the low beams is not connected to anything at the dimmer switch. However, remember that this wire is also connected to the other side of the indicator bulb. This will put twelve volts on one side of the indicator bulb and ground on the other, meaning the bulb will light. With the high beams selected the high beam fillament will have power and ground and the low beam fillament will have power and be grounded through the high beam indicator light, so everything will light up.

So why isn't my indicator light working? My theory is this: I switched my car to HIDs years ago. The first set I got were really nice and were the moving bulb type (the bulb actually moved forward and back for high/low beams). Unfortunately one of the bulbs eventually broke and I was unable to get a replacement. I bought another set of HIDs from a local shop (its no longer in business) that were less expensive and had HIDs for low beams and a separate standard bulb for high beams. Both kits had a relay box that connected to the light bulb socket. Because the moving kit was on all the time and moved the bulbs it would light up the same on either high or low. The new kit works differently in that instead of two separate states it would add the regular bulb to the HIDs for high beam. So for low beam it turns on the HID and for high beam it holds the HIDs on and adds the other bulb. I suspect that in holding the low beams on it is keeping the pin to the low beam switch grounded even when the high beam position is selected. In other words as long as the headlights are on in either high or low beam, there is ground on both sides of the indicator bulb so it will never light up.

The test to see if I'm right: Unplug the HID relay box from the car's harness. I'll do that tomorrow, its too dark and cold right now to do anything.
The fix: Rewire the indicator LED so it has +12V at all times and wire the negative side to the red-yellow wire on the dimmer. I'm not too keen to go hacking away at the new harness I just built for the gauges just yet, so I might just build my own relay box for the HIDs.

I'll post again when I test it out (probably tomorrow after work).

Thanks again for the support guys!


02-24-2011, 03:00 AM
I never thought of using pvc for the gauges housing. I think everything looks great. I think this might be something that should be stickyed in Interior/Exterior Aesthetic Modifications since you are going into how to change the cluster also.

02-24-2011, 06:35 PM
Just to correct what I said in my previous post before someone accuses me of being a bone head:

To disconnect the relay box is not a good enough test to see if the high beam indicator is working. Why? Well as can be seen in the diagram and as I stated before, twelve volts is supplied to the light socket, through the light, and is grounded depending on what position the dimmer switch is in. The best test would be to find a working stock headlight for the car and try it with that. I don’t think I have any of those left. FOR TESTING PURPOSES ONLY I could connect a jumper from the twelve volt supply to the headlights and the low beam connection at the socket. Then with the dimmer switch in the high beam position turn on the head lights and see if the indicator lights up. This is only good for testing because as soon as the dimmer switch is put back to low beam the twelve volts supplied to the headlight socket would have a direct path to ground, more commonly known as a short, and would blow the fuse for that headlight.

I have a feeling that the relay box contains a combination of transistor logic and relays for switching purposes and it is the transistors that are holding the one line to ground. If I confirm that this is the case I can’t simply fix it by turning my LED around and connecting it to twelve volt and grounding it to the red-yellow wire. This is because I simply don’t know what is happening in the relay box and supplying it with a voltage source through an LED when it isn’t expecting one can run the risk of damaging the circuitry. I could add a diode to the point where I would connect the LED and the light socket and that would work.

Regarding the remote start:

I kept going over the diagrams and couldn’t figure out why it wasn’t working. Even thought the light is not longer connected the park brake input for the alarm is wired into the junction block in Figure 2 of the schematics I previously posted which is still connected to the park brake switch and still goes to ground when the park brake is engaged. I finally had the “Aha!” moment and realised that the alarm does not have a pull up resistor built into its park brake input. This means that it can not independently sense when the park brake switch is grounded and needs the line it is connected to to actually switch from twelve volts (logic high) to ground (logic low). It will not work without the logic high state indicating that the brake is off. The logic high is provided by the twelve volts supplied to the park brake light. Without the other side being connected to ground there is twelve volts sitting on that line.

So to fix this I can move the light to the centre as I planned, but as I haven’t built that part yet I can just put a pull up resistor between twelve volts when the car is on and the line going to the park brake switch that the alarm is connected to. I don’t need a very big resistor and 1000 Ohm (1K) should do fine. I think I have some 1.2K resistors in my parts bin so I will try one of those tonight.


Edit: After thinking about it some more I have decided that I will rewire the high beam indicator. I will cut the wire that is grounded when the dimmer switch is in the high position and place a diode in this line such that it will not allow twelve volts to travel to the head light socket backwards and then wire the ground of the LED to this line. The diode is there to protect the unknown circuitry in the relay box. The only issue with this is that if I needed to put standard lights back in the car only one of the sets of filaments (hi beams or low beams) would be on at a time instead of low beams for low and low and high beams for high. The reason I am doing it this way is that it is quick and simple. Here's another schematic done in paint:

02-25-2011, 02:43 AM
Well I'm man enough to admit when I'm wrong, and that's just what I am with both the high beam indicator and the remote start.

I wired the high beam indicator like my diagram above. Because I wired the LED to twelve volts when the ignition is on the indicator will not light if the car is off and the high beams are on. Also the indicator will light when the car is running and the dimmer switch is in the high beam position even if the lights are turned off. It's not a big issue I can deal with it for now. After I had wired it in I tested the circuit and discovered that the reason the high beam indicator wasn't lighting was simply that both my high beam bulbs had burnt out. I'm feeling pretty stupid about that one. Fortunately I made this mod easily reversible: Instead of redoing the wiring to the old harness I simply wired up a spare blue LED I had and fit it in place and wired it to another molex connector.

As for the remote start, I am stumped. I wired in a light temporarily for the parking brake and tried it and it didn't work. I have a Viper 5901 and to remote start it I have to have the car running, press the footbrake, engage the parking brake, release the foot brake and press a button I mounted below the radio. The parking lights would then flash five times to tell me that the alarm is now keeping the car running. I can then remove the key, open the door, get out, close the door and arm the alarm. When the system is armed it turns off the car and it is now ready to be remote started. If there is an error in this set up then the alarm is supposed to flash the parking lights seven times and "REMOTE START ERROR" appears on the keyfob. What it is doing now is just going straight to "REMOTE START ERROR" on the keyfob without flashing the parking lights. Through a little trial and error I found that if I press the button when the ignition is off the lights will flash seven times and I get the error message on the keyfob. Same goes for when the key is in the accessory position. However, if the key is in the ignition on position and I press the button I just get the error with no flashing of the parking lights. So the only theory I have in mind right now is that when I ran the wires for the new boost gauge I may have broken the wire to the alarms "tach sense" input. When I wired in the alarm I followed the wiring instructions I found on a different site and connected the tach sense to the diagnostic port in the engine bay. Unfortunately I do not know when I will get a chance to check the alarm's inputs. It's tucked away in the car well enough that it's at least a three hour job just to get to it. For now I simply disconnected the wire from the diagnostic port (if I have broken it and it is shorted then I don't want to risk damaging anything its connected to). On the other hand I might be way off base and it could be something else.

I brought the low fuel level wire out the side of the instrument cluster and have it connected to a light and I can hook it up to the cigarette lighter when the fuel gauge gets low so I can calculate the values for my zener diode circuit. For now I also wired up the park brake signal to the low fuel warning LED. This one is bright enough that there is no chance of me driving off with the brake on. So at least there is some progress in the right direction.

I think I might head back to the electronics store tomorrow. All the LEDS are simply too bright, even with the extra resistance, so I will get some non super bright LEDs to replace them. Another lesson learned.


02-25-2011, 04:01 AM
Dude! that is in F'ing awesome! I would like to do something like that with my Alltrac one of these days!

03-02-2011, 05:11 PM
So... blessing in disguise? I disconnected the wire for the tach sense of the alarm from the diagnostic port last Thursday. Since then the car has been running better than it has in a long time. The stumble it had when I tried to rev the engine is gone. It idles much smoother, and the intermittent not wanting to accelerate from a stop is also gone.

I have a theory that somehow the wire I connected was loading the tach signal. I haven't quite figured out how this wire is connected to the ignitor yet. If it is connected to the IGt signal it could be modifying that causing the timing to be out. If it is connected to the negative terminal of the coil then it could be holding it high so even though the ignitor grounds that point to fire the coil the alarm wire is holding it above ground resulting in a miss timed or weaker spark.

I did put a metre on the wire I had put in and it has a resistance to ground of over two meg ohms. So it doesnít appear to be loading it. However, if there is a capacitance here then it may be causing the negative side of the coil to not be grounded properly and mess up the ignition that way. I didn't have my osciliscope and I definately didn't want to open the garage door so I could start the car (it's cold out right now).

Figure 7 of the link I posted above shows the tack output of the ignitor as well as the IGt (ECU telling the ignitor to fire), the IGf (ignitor telling the ECU that it has fired), and a filtered power input. Here is where I got all the information for the ignition system (unfortunately it says nothing of tach output): http://www.autoshop101.com/forms/h23.pdf

Back on track: I have picked up some non-super bright green and red LEDs to replace the ones in the dash. Unfortunately my local electronics store does not carry non-super bright blue LEDs. There just isnít a demand for them. The guy working the counter even told me that I was the first person to ever ask for non bright ones.

I also picked up my oil pressure gauge today. I was thinking that I could just swap it out for the Z-series gauge that is currently in the a-pillar and use the same sensor. I was wrong. The new gauge has a three wire sensor instead of a one wire sensor like the Z-series. This means that the gauge isnít relying on the sensors grounding through the engine/frame. Instead the gauge outputs a ground and a voltage to the sensor and the third wire inputs a voltage back to the gauge. Usually this makes for a more accurate reading (and it's more expensive, that makes it more accurate right... right?).

I was also poking around with the megasquirt tuning software and found that it has a preset built in for an Autometer 0-4V wideband A/F gauge. So now I am thinking about using that to feed a wide band A/F signal to the MS instead of the LC-1. I donít know which would be cheaper, but it would be nice to have all the gauges match. The Autometer gauge I'm considering is part number 4378.


03-02-2011, 06:08 PM
LOL, non bright LED's. Did you check the link that I sent you on those diffusing type LED's?

Interesting. Does the MS allow you to plot out the voltage of a custom wideband? Then you could take the LC1 output and feed it through just the same. If you can get a hold of a LC1 output chart/graph of some kind.

03-02-2011, 06:34 PM
Id personally have my tach on IGF not IGT. IGF doesnt directly interefere with the coil operation.

03-02-2011, 06:39 PM
Yeah I did check out that link. Unfortunately I deleted all the pm's in my inbox because it was full before I saved the link. D'oh!

The LC-1 output plots are well documented and easily found on the MS sites. The MS will work with pretty much any wideband so long as you know the two endpoints that the wideband will ouput. You then set up the MS with the tuning software such that one voltage is equivalent to the lowest reading of AFR and another voltage is equivalent to the highest reading of AFR. The code in the MS then interpolates the AFR assuming a linear output from the wideband. For example the LC-1's output is 0V=7.35:1AFR and 5V=22.39:1AFR. The Autometer gauge has the wideband controller built in and has a single output to go to a datalogger. This output has a range of 0 to 4 Volts. I don't yet know what its voltage corresponds to in terms of AFR yet. I have read on a different forum that it can be modified using the programming buttons on the front. People using the Autometer wideband are connecting the datalogger output to the Megasquirt for the AFR signal.

There are people using one of the LC-1's outputs to feed a wideband O2 signal to the Megasquirt and setting the other output to a 0-1V to drive an Autometer narrowband gauge. This works, but you would have to remember what each LED on the narrowband gauge represents for AFR as there are no numbers on that gauge. Initially I thought about trying to feed the signal from the LC-1 into the Autometer wideband gauge, but because the Autometer has the wideband controller built in I would have to open it up and bypass that. Frankly that's more trouble than it's worth, especially since I would have to buy the gauge to start with.

Cost wise the Autometer gauge is $299 at Jegs, which is similar to the price I would pay at my local speed shop. The LC-1 with XD-16 gauge at diyautotune is $299. So cost isn't really going to be a deciding factor. At the momment I am leaning towards the Autometer just so I can have all my gauges match.


03-02-2011, 06:46 PM
Id personally have my tach on IGF not IGT. IGF doesnt directly interefere with the coil operation.

That's one of the things I was thinking about trying, and is a good idea. The only concern with using the IGf signal is that if my wiring is loading the circuit and causes a certain number of spikes to be missed by the ECU, the ECU will shut down the ignition circuit to avoid damaging the ignitor and/or coil thinking that it isn't firing.

Before I try anything though I have to find out if the problem is in the wire I installed or in the alarm itself. It may just be a simple case of redoing the wire, in which case I will make it much shorter and connect it to the same wire that is driving my tach (in the dash).

The Megasquirt it has a separate tach driver built in that runs independantly of the ignition outputs, so I could just live without remote start until I install it.

03-03-2011, 07:33 PM
Here's the link: http://store.garage1217.com/custom-twist-socket-aluminum-ringed-high-output-bulb.html

Here is a good thread;


They have a lot of different bulbs but are pretty cool. At some point I want to convert mine to either orange or blue in the 205 to match my deck/gauges.

03-03-2011, 09:25 PM
Oh yeah and by the way, prosport gauges are garbage. So, yeah. Just a heads up.

03-04-2011, 12:47 AM
Hey Chris, thanks for the link! I checked out that thread, those LEDs look awesome. I like the interior lighting and the licence plate lights too.

I've never used the Prosport gauges. I only know a little about them. I know that they cost significantly less than the Autometers I chose. I have heard that some people have trouble reading them in the sunlight.


03-04-2011, 01:40 AM
For visibility, it depends which series you use. I use the Prosport 45mm series in my ST205, which was the driving factor in my purchase since I've custom mounted them in my DIN slot. Lense is clear, not smoked, so visibility is not an issue. Selection of 45mm gauges is very limited, so it was primarily finding some that I liked aesthetically and had the gauges that I wanted. All electronic. Mine have held up just fine for a year and a half now, I like them and have no reason to not. I've definitely used crappier gauges.

03-04-2011, 02:34 AM
I've never even thought about 45mm gauges. Like I said, I have no experience with them so I can't say either way. I've only ever had experience with Greddy, Autometer, and some really cheap gauges in a friends car (Sunpro I think, came from Auto Value). Of all those, so far I like the Ultra Lite Autometers the best. Mind you I am obviously biased lol.

Oh, and yay for page two!


03-08-2011, 05:26 PM

The new oil pressure gauge is in. I have it set such that anytime the oil pressure drops below 30psi the warning light comes on. I changed out the sensor when I did an oil change last night and all the wiring was fairly simple. As with the boost gauge sensor I had to extend the harness a few feet.

As you can see I also changed out the oil temperature gauge for an EGT gauge. Iíve had this gauge since I put the new exhaust on but never got around to mounting it. I put this one in so I can get used to it being there before changing it for an Ultra Lite series gauge. Also the water injection LEDs are not mounted yet. Because I'm using a new mounting system I have to get new LEDs.

This left me with no way to monitor the temperature of the engine, so I re-routed the sensor wire for the oil temperature gauge to the centre consol and put the gauge there. This gauge currently isnít mounted and does fall over going around corners, but I just wanted it to be there for me to look at occasionally until I get the chance to build my centre consol gauge cluster.


03-11-2011, 10:41 PM
Well my gauge project has hit a bit of a setback. While I was under the car installing the oil pressure sensor I found an oil leak. Okay, a few oil leaks. As with many MK1 MR2's the exhaust side of the engine was covered in oil. This is nothing new, but I found a fairly substancial leak at the threads of one of the hoses to the oil filter relocation kit. The hoses that came with the kit have a fitting at one end that swivels and a fitting at the other end that is solid. The solid ends are screwed into the oil filter relocator, which is then installed on the car and then the swivelling ends are screwed into the adapter on the block. In my case the feed line to the oil filter is leaking at the oil filter relocator. This is a universal kit and as such both the feed and return hoses are far to long for my needs. I decided that I would fix this once and for all.

I had already placed an order to kbox for new cam cover gaskets, new oil cooler hoses and washers, new oil filter sandwich plate orings and new distributor seals. That should take care of the "standard" leaks. For the oil filter relocation leaks I dipped into my gauge budget and got this:

Aeroquip -10 braided hose and fittings. I have four NPT to AN adapters, two straight hose connectors and two forty five degree connectors. I found several posts online about people having trouble putting the hose ends on so I gave it a try last night. I wrapped the hose in masking tape, used my dremel with a cutoff wheel to cut the hose, cleaned it up, oiled the outside of the hose, oiled the inside of the bit that goes over the hose, pushed the hose into the outter bit, oiled up the inner bit, stuck it in a vice and pushed on the hose while turning the outter bit to get it on. It was actually much easier than I thought it would be:

So hopefully by the end of the weekend I'll have these leaks taken care of and I can focus on building the centre dash part for three more gauges.


03-12-2011, 04:58 PM
Damn Im diggin that gauge setup if only mycluster didn't work I'd be doing that to mine, but it's all working good but maybe in future. It's all looking good though keep it up.

03-22-2011, 05:14 PM
Following the link that ChrisD posted I ordered some LEDs. I got two of the dash LEDs in blue, the LED dome light and two more LEDs for the licence plate lights.

Because of the weather so far I've only put in the dome light. It is much brighter than before, but isn't really tied down so it moves around under the cover.

I tested one of the blue dash LEDs and it is bright enough to warrant not looking directly into it. I hope to have them in by next Monday. I will do a comparison with the Autometer LED in one of the gauges and the new LED in the other.


03-30-2011, 02:50 AM
Well I've made zero progress on this. Work is sending me to Christchurch NZ to do some seismic work and I've had to spend all of yesterday and today getting all the gear cleaned and packed. I'll be leaving on Friday. Three weeks back in the country I was born on the company's dime! Mind you I have to work the entire time I'm there. I'll have to pick this up again when I get back.


03-30-2011, 03:22 AM
Nice progress and hope the trip goes well.

06-28-2011, 03:29 AM
Well I tried the new LED in the tachometre. Since it is trying to be summer here it is too light to see what it looks like in the dark. So I ignored some advice I got in my childhood and put the cluster and my head in a garbage back to check it out. It was disappointing. I could not see a difference between the new LED and the old one that was still in the speedometre. So I have to start looking at other solutions. I'm thinking of trying to build my own little LED cluster to fit in the gauges.