TCC unlock wire

[eran tomer]

Eran, that purple wire just transfers or interrupts 12vdc to the ecm/pcm for it to determine if/when to apply/disengage TCC. So, when you find your purple wire, wherever it is, just severe it before the truck's original computer, and attach your new harness TCC wire to the switch side of the truck's TCC wire. Your new PCM will take care of the rest. Good luck with your swap. BTW, that switch I showed earlier, is actually pretty easy to install/remove once you get to it. You may have to be a contortionist to get to it, but it's doable

I've found this wire behinde the glove box on the c200 connector and on one of the pcm connectors.
But they want another wire that does the opposite- gives 12V when the brakes are applied so the dbw throttle body can function. where do I find it? it's a 95 suburban and the factory electrical manual isn't clear.

 

[Leeztruk]

Ok, gonna work from memory here. My last truck ('80 C10 w/dbw 5.3 & 4l60E ), for my TCC I had a 2 sided brake switch. One side constant hot until brake applied, one side off until brakes applied (brake lights on). In your case you've got a different switch entirely from the one I showed earlier, but still functions similarly. GM's wiring colors are pretty consistent and the purple wire we've been discussing is actually an ABS wire. If you go to your ABS module, find your purple wire and check for constant 12vdc with KOEO, then voltage goes away when brake applied. Splice into that for your TCC to the PCM. The DBW wiring from the throttle body ties into your TAC module (you have a TAC I presume). For the switched power when brakes are applied, you can splice into your power feed to the brake lights from the brake light switch (not sure of your truck's wiring color, my '89 is pink/white). Hopefully this will help you some