View Full Version : System Ten Stereo System Mystery

06-01-2013, 03:00 AM
Heres a mystery. I just bought a new/used System Ten Stereo system on Ebay that came out of a '91 4 Runner to replace the one in my 1990 Celica. It is in 2 parts, like the one in my Celica, and the harness plug in the back is exactly the same. To give you some background, my system only produces sound from the AM/FM radio; when I insert a CD or cassette, the display shows that is is playing, but produces no sound. When I replaced the the unt with the one I bought on Ebay, sound/volume was great on the radio and also when I inserted a cassette, but when I put in a CD, very little sound was coming out of the left side speakers, and only a little bit more out of the right side speakers. I decided to switch the CD units to see what would happen. Well the old CD player produces sound out of both sides of the speaker system but just above audible when paired with the new/used AM/FM cassette part. The new/used CD player produces no sound when paired with my old AM/FM cassette part.
It sound like the problem lies in the base unit, the one that housed the AM/FM cassette.
Any thoughts?

06-01-2013, 05:34 PM
Most likely answer is a dying opamp or bad capacitors or both. Just get a new deck and a pocket and call it a day.

06-01-2013, 06:54 PM
Woking on that, the system ten in the '90 Celica is challenging to say the least. I am probably gonna have to eventutually scrap the factory amp and do everything from scratch. Not ready to do that yet since it would be a first for me, have to do some more research and get recommendations on what head unit to replace the factory stereo with and matching amp. Haven't been too electronically challenged in the past and will have to look at some of the stickies on this one.

06-01-2013, 11:16 PM
You can for the short term as an easy install, give up the two door speakers and use the separate two plugs that are behind the radio. You'll see them attached to a bracket on the passenger side. Those are the "normal" plugs for a Celica, and most Toyotas for that matter. They will give you the front dash speakers and tweeters, and the rear speakers and tweeters. However, didn't you buy one of the UK 90/91 System 10 adapters? If so, just get a decent aftermarket deck with a four channel line out.

06-02-2013, 05:33 AM
I did buy one of them, but having trouble getting my aftermarket for work with it. When I hooked it up last year, the aftermarket powered on, but I didn't get any sound. Just a few days ago I hooked it up again, but no power to the aftermarket. I put my factory stereo back just to check, and it powered up ok. I checked the connections on my aftermarket with the the adapter (MR2) that I bought overseas and it seemed ok. Goining to have another look at it. In the meantime I can use the cassette player with an adapter to use with my smartphone to play music, and it is a lot louder that when i was using it with my bluetooth adapter.

06-02-2013, 07:01 AM
Can you post pictures of your wiring? Also, did you check the fuse on the aftermarket deck?

06-03-2013, 04:19 AM
Fuse(s) must be inside the unit, don't know when it would have gone bad since I only put it in once.

06-03-2013, 01:35 PM
It's usually on the back, and gets covered up by the wiring plug.

06-03-2013, 11:09 PM
Well, this is interesting. The aftermarktet head unit has a slot for a 15 amp fuse, and the fuse is missing! Don't know how that happened, don't remember seeing it before. Now I have to figure what kind of fuse (metal and glass I assume) and where to get it. On a side note, I have a factory system Ten from a '93 Celica that I pulled from the junk yard which is a 15 pin plug, but still only uses 14 connectors that correspond with the 14 wires on the other adapter for my '90 celica. I pulled out a 14 pin connector from a non working factory amp that matches the one in my celica and soldiered the wires from a 15 pin connector that I cut when I pulled the unit from the '93 celica to the connector from the amp. I am going to see if it will work, it should since the wire colors all match. Has anyone else tried this?

06-03-2013, 11:27 PM
Don't solder, just remove the pins and place your old ones in. Then you need to get the 93 harness.

However, you have a known working harness, why dick with it?

Sell the 93 connector to somebody who doesn't have one and wants one for like $5 or $10 plus shipping or something.

06-04-2013, 06:00 AM
I have a harness that I cut out of the celica along with the head unit. Problem is the connector is different than the one in my Celica, but the wires are the same. The connector I pulled from the amp has long metal pins (the ones soldiered on the board) that I was able to remove intact when I desoldiered the connector from the board. So I soldiered the wires from the system 10 connector to the pins on the connector from the amp. All I have to do is get something to keep the wires from arc to one another. A friend of mine told me that was something to spray on that acted as an insulator for each individual connector.
As for the aftermarket head unit, I think the fuse in one of the new type in autos, not the metal and glass. I am at work right now and will look at it when I get home. Then I will try it in my Celica.
I'll let everyone now if my mod works on the other system ten. Hope I don't blow a fuse! (or amp).

06-21-2013, 06:11 AM
Well, I didn't blow a fuse, but wanted to let everyone know that the makeshift adapter did work. However the pull from the celica had sound issues that were worse than my system, CD player would not play - just spit out the CD, sound from the AM/FM player was only on one side. But again the good new is that it worked!

06-21-2013, 06:33 AM
Also pursuing other options with my stock stereo beside putting in a aftermarket. Some of the Camarys and 4Runners had system 10 stereo systems that will fit a 1990 celica system that have the 14 pin. I just ordered a CD changer from EBAY that has the identical round connector on the AM/FM cassette section of my System 10; I'll let everyone know if it works.
P.S. I did put an aftermarket system using the Autoleads adapter, but like other have found out I got sound out of all the speakers with the exception of the door bass. I may have hooked up the amp turn on wire wrong and am going to persue that line as well. But the sound coming out was great! No humming or feedback.

Luis C
06-21-2013, 09:11 PM
I used to have a GT-S with a System 10, the head unit was dodgy so I replaced it with a Pioneer one witch worked great, I used the stock wiring without cutting or splicing any wires, BUT dont ask me how it was done since I had to ask a friend to come over and do it for me, luckily he was a car audio buff at the time and was also majoring in electronic engineering so with a digital multimeter and LOTS of patience he figured out the whole shebang.
It is doable but it will take time, patience and knowledge.

06-22-2013, 01:09 AM
Got the CD changer in the mail today, installed it and it works great! Fantastic sound out of all speakers and still retains the AM/FM cassette portion which also is working in fantastic condition. So it look like stereo parts are interchangable between different toyota cars that were made around the same time. The cd changer was out of a 92 Camry. It fits in the dash above the AM/FM cassette player and has a cartridge that fits 3 CDs that you push in and eject. On the back is a round plug adapter that fits perfectly where the stock CD player hooked into.