Ground wires on back of head
 

I got a used 91-92 Z28 harness and I am going through and inspecting every wire and will be fixing any issues and Tessa taping and split looming it. I found a wiring diagram and I think these 3 black/white tracer wires are grounds to the back of the head. I believe the tan wire is too. The diagram I found shows this should be on passenger side but these are definitely drivers side.
Also, that little orange wire, does anyone know what was supposed to be on that cut end?
https://cimg4.ibsrv.net/gimg/www.thi...8e8383ac94.jpg
https://cimg5.ibsrv.net/gimg/www.thi...ea1b016fe2.jpg

Re: Ground wires on back of head
 

Bump? Anyone out there

Re: Ground wires on back of head
 

Trace them (check continuity) to the pinout on the other end and look that location up in the diagram.

Re: Ground wires on back of head
 

The diagram I was looking at doesn't even seem to jive with these wires. Does the C100 etc show ground locations

Re: Ground wires on back of head
 

Pretty sure the tan wire isn't a ground.

Oil pressure sending unit maybe?

Re: Ground wires on back of head
 

I thought that as well but this harness has the 3 wire Oil pressure sender. I need to find the diagram again but It showed 3 black/white wires as grounds and I think it showed a tan as "Ground reference" but I've been super sick and on meds so maybe I dreamed it haha

Re: Ground wires on back of head
 

Have you reviewed the wire diagrams available on https://austinthirdgen.org/.

Re: Ground wires on back of head
 

Yep, thats where I found them before, going to re-check now

Re: Ground wires on back of head
 

Ok so 112 is the driver side head ground and 118 is passenger side head. This is where I am confused. In that diagram, it shows 112 as having 2 BLK/WHT and the TAN but I have an extra BLK/WHT making 3 total plus the TAN.

Re: Ground wires on back of head
 

Ok! I OHM'd it and found it in the 32 pin green ECM connector. My mystery TAN wire is the O2 sensor ground. Now, does it ground at the head with the BLK/WHT wires or somewhere else?

Re: Ground wires on back of head
 

Ok so my BLK/WHT wires are apparently ECM ground, Injector grounds. The last one to figure out is this orange wire and it goes to a clear connector and is in position "M" but I cannot figure out what connector this is.

https://cimg6.ibsrv.net/gimg/www.thi...2c0edb9c28.jpg

Re: Ground wires on back of head
 

I think that is the connector that interfaces with the body. Some of the wires go to the ALDL. Another wire goes to the check engine light. The stock fuel pump 12+ goes through that connector. Not sure about the "M" wire. I will have to check my 92 F-body shop manual.

Update: I checked my 92 Camaro shop manual. I think that is connector C207. Pin "M" is stated to be orange and it is listed as "Interior Lights, Underhood Light."

Fred

Re: Ground wires on back of head
 

Yep I found out its the underhood light and the red plug next to it is the fuel pump prime? I think I have most of the cut/damaged wires figure out now. Hopefully anyway

Re: Ground wires on back of head
 

If you have any other issues, post it up and hopefully we can help.

Fred