90 Wiring Diagram - looking for wire "x"

[lemuttman]

Waiting on parts so we moved to interior and removing all the junk wiring that is no longer needed after the LS swap. We also picked up a full round of AutoMeter gauges. Anyone have or have a good source for a full electrical schematic?

Thanks for the links to the PDF with all the schematic details!

Changing the title to include - Help me find "x" wire!

 

[mechted]

http://67-72chevytrucks.com/vboard/showpost.php?p=5621043&postcount=1

 

[lemuttman]

Thank You!

 

[nvrenuf]

@lemuttman I'm not sure what you want to keep but I just went through this on my '91. I eliminated my instrument cluster (all Autometer), heating and a/c and all of the TBI/computer wiring. It turned in to a PITA for me so bought a harness from a Facebook vendor named "Harnessworx". He let me customize what I wanted to keep and delete so I ended up with a fuse box with harness just for all of the steering column switches and the headlight switch with some extra constant 12v and ignition 12v wires for half of what Painless wants.

 

[lemuttman]

@lemuttman I'm not sure what you want to keep but I just went through this on my '91. I eliminated my instrument cluster (all Autometer), heating and a/c and all of the TBI/computer wiring. It turned in to a PITA for me so bought a harness from a Facebook vendor named "Harnessworx". He let me customize what I wanted to keep and delete so I ended up with a fuse box with harness just for all of the steering column switches and the headlight switch with some extra constant 12v and ignition 12v wires for half of what Painless wants.

Thanks! We may have to go this route as well.

 

[lemuttman]

Again thanks in advance for your help!

After spending a great deal of time learning the in/outs of the schematics I fairly comfortable navigating around. We have done a great job of removing/securing all the unnecessary wires as we hook up our AutoMeter gauges, I have run across a couple of wires that I just can't figure out what they go too.

1 - Purple w/white Strip twisted with Light Green and Black - I am pretty sure this is the VSS (Vehicle Speed Sensor) which is no longer needed if the LS was running before.
Wires go into the firewall passenger side and connects inside above old ECM
2 - Green (maybe Dark Green) that splits into two Green wires via a connector center of the firewall - I can't find this wire or connector anywhere in the PDF.

 

[Big Ray]

I found a factory wiring manual on eBay cheap. Due to Christmas stuff I won't be able to dig mine out till sat. Its still buried from our move when we bought this place...

 

[Big Ray]

Jus did a quick search, its hiding somewhere. I will find it and get back to you.

 

[Big Ray]

Does that green wire go through the firewall or stays in the cab? Thinking that may be a speaker wire....

 

[500$k5]

If the green wire is on the engine side of the firewall, with a connector, it could be for the a/c compressor.

 

[Gentleman Jimmy]

If the green wire is on the engine side of the firewall, with a connector, it could be for the a/c compressor.

X2 on this.

The twisted pair is the VSS. The LS will run without it, but I wouldn’t get rid of it. even if you have a manual trans sometimes the ecu will need a signal to keep it from stalling when coming to a stop depending on the tuning.

 

[lemuttman]

Yes, wire(s) are on the engine bay side.

X2 on this.

The twisted pair is the VSS. The LS will run without it, but I wouldn’t get rid of it. even if you have a manual trans sometimes the ecu will need a signal to keep it from stalling when coming to a stop depending on the tuning.

Interesting - truck is a automatic. With confirmation it is the VSS I will roll under it and see if anything is plugged into the sensor. Maybe (fingers crossed) the PCM is steady plugged in directly vs going through factory wiring.

 

[500$k5]

The green wires are for the a/c compressor.

 

[Big Ray]

I have not forgotten you, still cannot locate my manual

There will be some serious spring cleaning and organizing this year, Daddy has work to do!