What does THIS go to???

[munice]

hey guys, what did this big clear guy plug into?

It splits off from the main harness feeding the ECM

I've got the harness out of an 89 c2500 and ive been hacking it into my 87 but i don't have the rest of the truck to see what I'm missing.. and I've traced a power source for the ECM ends up here as well as the crank signal and power for the TBI injectors and a few other crucial wires. I figured it'd be fairly straight forward to swap in the 454 TBI into my truck that had a 350 TBI but now that i look at it I should've just gone to a carb... but ohwell too late now... ive got all this stuff in here and Its cranking, we've got spark and the fuel pump running but the ECM isnt letting the injectors fire even with power.. SO I guess this plug went into the dash harness or something? cause some of the wires are getting power starting at this plug, and some wires are getting a signal input from here, I think we'll end up just tracing everything back and refeeding all the wires on this plug, but i'd like to know what it was.

[ChevLoRay]

My suggestion is to use the wiring schematics for the donor harness and the vehicle you intend to mate it with, in order to learn what each wire is for.

Hopefully, someone will recognize that piece and let you and us know.

[69c10stepside]

That for sure goes into the dash wiring, it is in the group of wires right under the ecm, down under the glove box area. Anything past that, I can look into when I get back to the shop tonight if somebody else doesn't chime in.