PDA

View Full Version : 91 all trac A/C problem - light, but no air



Dirk
06-18-2008, 10:24 PM
Hi all,

So, I've got a '91 all trac who's A/C system was overhauled about, oh, 2-3 years ago, because it wasn't idling up properly when the A/C was on - the dealer ended up replacing almost everything in the system (mostly at their cost, to their credit) to track it down, and, after they did, it worked amazingly well.

However, this year, I suddenly have no A/C - pressing the button turns on the little green light (it's not flashing, which is, I understand, the usual error code), but... nothing happens. No cold air, no idle up, no compressor noise, nothing. :(

As far as I know, there should still be a charge in the system - it never leaked before, anyway. Any ideas where to start to figure out where the problem is? Any way to 'force' the compressor to engage (temporarily) to see if it's working, etc?

Shadowlife25
06-19-2008, 12:41 AM
It sounds to me that you need a re-charge. Mine did the same thing when it was out of refrigerant. Hook up a pressure gauge to the nipple on the passenger fender-well and see what your numbers are. Let us know what you find, and welcome to C-Tech! :D

Dirk
06-24-2008, 04:16 PM
It sounds to me that you need a re-charge. Mine did the same thing when it was out of refrigerant. Hook up a pressure gauge to the nipple on the passenger fender-well and see what your numbers are. Let us know what you find, and welcome to C-Tech! :D

I suppose it's possible, although I've never had a leak in the system before. Had no idea there was an easily accessible place to check the pressure, although I suppose that would make sense. :) Is this something you can just check with something like a tire pressure gauge, or do I need something more specific?

If it is empty, guess I'll be looking at conversion options - can't get freon up here, and I'm not sure it's worth hauling across the border again.

Thanks for the help!

Shadowlife25
06-24-2008, 11:17 PM
You may be able to check it with a tire pressure guage. Give it a shot.

cs363
06-25-2008, 07:30 AM
Check the wiring to the clutch on the compressor too - my car had exact same symptoms, went through everything including trying to recharge only to find that one of the wires had broken :)

Dirk
06-26-2008, 10:38 PM
Okay - looks like I've got a few things to check this weekend. Time to figure out where all the A/C pieces are under the hood. ;)

Shadowlife25
06-27-2008, 05:08 AM
The BGB on the homepage should clear that up for you. ;)

Dirk
07-04-2008, 04:04 AM
Okay.... so, I'm still lost. <sigh>. Shadowlife25 mentioned checking the pressure at the nipple on the passenger fender... but I don't see anything obvious on the passenger fender area. There's a connector right by the sight glass by the receiver, on the driver's side - would that do?

cs363 - I'm not even sure how the heck you get to the wiring for the compressor - it looks like it's stacked under the alternator....?? Either that, or I'm really looking at the wrong things - the diagrams in the BGB aren't terribly helpful to me. What can I say - I'm much better with computer equipment. ;)

Anyone have a picture of exactly what I'm looking for? Or I can take some of my car, and you can point me in the right direction, if you're willing.

Thanks.

cs363
07-05-2008, 01:50 AM
Okay.... so, I'm still lost. <sigh>. Shadowlife25 mentioned checking the pressure at the nipple on the passenger fender... but I don't see anything obvious on the passenger fender area. There's a connector right by the sight glass by the receiver, on the driver's side - would that do?

cs363 - I'm not even sure how the heck you get to the wiring for the compressor - it looks like it's stacked under the alternator....?? Either that, or I'm really looking at the wrong things - the diagrams in the BGB aren't terribly helpful to me. What can I say - I'm much better with computer equipment. ;)

Anyone have a picture of exactly what I'm looking for? Or I can take some of my car, and you can point me in the right direction, if you're willing.

Thanks.

Hey Dirk,
You are looking in the right place for the wiring, but you'll probably need a torch the wiring runs across the top of the compressor. There will be a couple of square white wiring connectors there, try and follow the wires to the clutch hub (behind the drive belt pulley) usually if they break its close to the clutch unit.

The pressure nipple by the sight glass is the high pressure one (usually has a red cap) the one you are looking for is on the hard a/c line and usually has a blue or black cap. You can see it in this pic on the right side of picture just above the air filter, though this car has the steering wheel on the 'proper' side(lol) so yours should be the opposite side.

Rix86
07-05-2008, 03:04 AM
tire pressure guage won't to a damn bit of good.
Take it back to the dealer or other qualified shop.

cs363
07-05-2008, 03:21 AM
tire pressure guage won't to a damn bit of good.
Take it back to the dealer or other qualified shop.


I agree -hadn't noticed that post. Unless you have an a/c pressure gauge kit (unlikely) do as Rix says and take it to a professional. If you must go into the pressurised system because of budget or just plain old adventure...... get one of those proper DIY kits that you guys can get over in the US from Wlmart or whatever. I believe most of the better ones come with the correct fittings and a gauge.
But I would stress again that if you are unsure about what you are doing, take it to the a/c guys.

Dirk
07-06-2008, 01:05 AM
Thanks for the help folks - at least I have a better idea of where I'm looking now. :)

The problem is that I'm in Canada - and freon systems are no longer legal here. All a shop is technically allowed to do is drain & convert them to R134a - now, obviously, if the problem is a wiring issue or something, and there's nothing wrong with the charge, then I don't really want to do that.

I have a friend who works for a dealership who says that he thinks they still have their old equipment - he's going to check to see if someone there would at least be willing just to check the pressure (if any) in the system. I'm in full agreement - I know next to nothing about A/C systems, and would prefer that someone with training/tools deal with potentially high-pressure gases.

That's why I'd like to be able to narrow down the problem - if it's just a connector or sensor, then it's easy - if I have to convert the whole system, I have to start looking at costs, how well it'll perform afterwards, etc.

cs363
07-06-2008, 01:12 AM
probably a good opportunity to have your system inspected and changed over to R134a (unless it already has been) - a/c systems should be checked/serviced semi-regularly anyway and by the sounds of it yours probably hasn;t been serviced for some time I'm guessing.
I don't think it should be very expensive to have the system converted, it certainly isn't here.
Generally speaking when things go bad in a/c land the charge is the first thing that gets checked, when they change the gas they usually put in a dye that helps with leak checking as well as a lubricant pack that lubricates the pump and other components.