Alarm system tampered with by previous owner
 

Excuse this if it is a repeat. I saw a lot of alarm posts but couldn't really see a full blown wiring diagram for my car. After buying this 92 Supra, I discovered afterwards the dome lights and radio did not work. Prying into the under steering will enclosure, I discovered a computer that was disconnected entirely from the 12 pin? harness and a several wires bunched together with a wire nut. (can give all the wires color codes when I get to it) When I attempted to plug the computer back in, of course the alarm went off. The car runs and starts perfectly so I don't want to try to get the radio working only to disable the starter or short something out. My Haynes manual has not come in the mail.
Today we are starting a work day on this project car with lower and upper control bushings going in so we will be working on it already and thought we could fix the radio and dome lights if someone had the wiring diagram and any hints as to potential problems that could occur if we (my son and I) pry into this thing. Let me know if anyone can help

You posted this in the FAQ section. That's essentially a reference area and not for general discussion. I've moved it to the main MKIII section where it belongs.


Haynes is a poor reference for most vehicles and the Supra isn't an exception. Return it and purchase Toyota's Service manuals... You'll be glad you did in the end. They're worth every penny of the MSRP but if you can get them used well, all the better. Here's an online version for the '90 Supra, both TSRM and TEWD (that's Toyota Service and Repair Manual and Toyota Electrical and Wiring Diagrams):

http://www.cygnusx1.net/Supra/Library/TSRM/MK3/
http://www.cygnusx1.net/Supra/Library/TEWD/MK3/

The alarm system will not disable the radio in stock form so no worries there... :P In my post in the FAQ section I've covered what has to be done to reset and/or delete the factory alarm system. Read it and reverse it if you want to enable the system. You'll most likely need to replace the lock switches in the doors though. Personally, I'd replace it with a modern alarm.

I was reading this thread looking for a wiring diagram and wanted to know if there's a thread that shows step by step to wire up an manual r145 to an at setup. I have two supras that have been converted but my 89 has bad wiring like ignition is wired straight to the starter. That and the neutral safety switch are giving me the check engine light.
Please help