Hi, so im rewiring this cut harness. it was cut because the harness from the motor 91 305tpi the main fuse block didnt match. so, i have a wire that is Brown/white that is supposed to go to gauge cluster or used for cel.

This wire has 12v in the on position and when its grounded, the service engine light comes on.

Now my question is, if i wire this brn/wht wire with 12v to the ecm brn/white wire thats for the ses, will the 12v directly to the ecm harm it? or does it normally have 12v at the ses connector at the ecm?

Im afraid to connect it and kill my ecm. but those are the only brn/white wires, and i know that it is for the ses because when its grounded the light turns on.

Thanks for any help

 

Nearly every item controlled by the ECM has 12V going to it and then it is controlled
by going to ground at the ECM end

 

thanks for the info. ill hook up the light tomorrow and then try to retrieve the codes.

 

ok. so i wired the brn/white wire that is for the ses light to the brown wht wire i found coming from a plug near the ecm. if i follow the wire from the ecm, it goes to an extra plug that i dont have wired to anything because i dont know what its for. i have the ecm pinout for the 91 camaro tpi. but i dont see this 4th connector. heres what it looks like. it has a lot of pink/black wires and it looks important, but it doesnt make sense for the swap i have. i might have wired it wrong if this connector is one of the main outputs for my inject signals and what not. any idea?

 

this clear plug has all the wires to operate the injectors and other sensors. had to wire it in. still working on it.

 

Bought all new shrink wrap and more solder today. gonna start fresh with what i know about that clear plug and permanently wire these until its perfecto. I WILL FIGURE THIS OUT!!

 

That connector is the C207... May or may not have a diagram in the service manual (GM manual, doubt it's in Chilton's and I know it's not in Haynes). While you're at it, make sure all of the other wires are in the right holes or things like the fuel injectors aren't going to work (VATS fuel enable and injector power wires run through that connector as well as emissions and other power wires).

:edit: And get rid of that quick splice before it actually CUTS the wire it's attached to.

 

 

Thanks guys. Ive got diagrams out the WaHoo right now. Also, ive come to have a pretty good understanding of the function and place of all the wires. ive completely rewired that clear plug(C207) and soldered, shrink wrapped, and conduit them. starting to look professional. i would like to haVE it completely rewired and running by the end of this week.
Thanks!!
Dean

 

It's so nice to see somebody fixing a harness for a change.

 

Ill get some pics of the finished job. i love cleaning up an engine bay. So i can tolerate wiring. Been enjoying this one though because now that it all makes sense, theres not much to do. and its so satisfying to see the end product.
ps. VSS retrofit came in and installed in 1 minute. very NIIICE!

 

I'm looking forward to seeing those pics. Solder is definitely a good "upgrade" to the wiring; unlike crimping, it can last for 100 years.

 

Yeah, i gotta use the crimps and jumper block things while i figure the mess out. once i understand, then thats when the beauty begins.
peace
Dean