Problem with Metra harness 70-8112 for a '90 ST185 w/sys 10

I found this cached page from the old forum on google:

http://216.239.41.104/search?q=cache:Gw ... ness&hl=en

Cliffs notes version: The Metra 70-8112 harness doesn't work on the 1990 models' System 10 setup.

My GF's is a 1990 with the System 10. Does anyone have experience with the Metra 70-8112 harness in a 1990? I know the standard two piece harness for a Toyota doesn't work because I had a spare one and it didnt fit at all.

I just need to install an aftermarket deck and keep using the stock amp. If this is possible to do and have all 10 speakers working, please tell me how I can without butchering the stock wiring. Thanks in advance.

Well actually with our setup in the 90 model, the standard toyota harness does work =}. When you have the unit out look to the back passenger side of the center console, and you should see 2 connectors. Those are what you'll plug the standard toyota harness into, your left and right channels. Now that will just run the 2 sets of component speakers. Now to get the drivers in the doors running, the best way I recall is to get a small amp and just find their wires going to the stock amp and wire that together. There are a few other ways to go about it though. I'm pretty sure celica.net has quite a few topics on it. Personally I just run to the 2 component sets in my car and haven't had the door drivers powered in years.