87 R/V series bulkhead connector pinout???

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throttle out

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Let me first apologize because I simply find the wiring schematics we have at our disposal for our trucks to be impossible to read.
I am trying to find just a simple pin out of what wire is what on the bulkhead connector of my 87 V10 pickup. My truck had a TBI 5.7 in it and I just got my LS swap somewhat completed (running and driving). I'm getting ready to wire in my OBD2 port and am certain my truck already has provisions for this wiring. My dash has a "check engine" light and I want to use it, and I would imagine there is already a serial line coming through somewhere as well that I should be able to utilize. I understand Its only four wires to run, but would like to integrate with my truck as best I can.

Any help would be AWESOME!!!!!

This may be in the wrong location and I will move it if need be.

Thanks in advance
Sammy
 

1987 GMC Jimmy

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Let me first apologize because I simply find the wiring schematics we have at our disposal for our trucks to be impossible to read.
I am trying to find just a simple pin out of what wire is what on the bulkhead connector of my 87 V10 pickup. My truck had a TBI 5.7 in it and I just got my LS swap somewhat completed (running and driving). I'm getting ready to wire in my OBD2 port and am certain my truck already has provisions for this wiring. My dash has a "check engine" light and I want to use it, and I would imagine there is already a serial line coming through somewhere as well that I should be able to utilize. I understand Its only four wires to run, but would like to integrate with my truck as best I can.

Any help would be AWESOME!!!!!

This may be in the wrong location and I will move it if need be.

Thanks in advance
Sammy
This?
 

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HotRodPC

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I think that above image is of the OBD1 ALDL pinout. I believe he's wanting the engine bay wiring harness pinout off the firewall.

I'd like the same thing for an 85 Gas and Diesel to convert my OEM 6.2 to Gas. I too have problems following the complete wiring schematics. I'd prefer a pinout description like this ALDL diagram telling which each pin is for but for the bulkhead pinout.
 

1987 GMC Jimmy

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I think that above image is of the OBD1 ALDL pinout. I believe he's wanting the engine bay wiring harness pinout off the firewall.

I'd like the same thing for an 85 Gas and Diesel to convert my OEM 6.2 to Gas. I too have problems following the complete wiring schematics. I'd prefer a pinout description like this ALDL diagram telling which each pin is for but for the bulkhead pinout.

Ahh, I gotcha.
 

throttle out

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Hotrod is exactly correct. Still unsure why this is such elusive info.

Needing this to integrate my LS motor to my factory gauges. But also as my truck was factory TBI, I'm pretty sure there was also a serial data line in the mix as well as a CEL light lead.. Would be nice to utilize it instead of running another.
 
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foamypirate

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Hotrod is exactly correct. Still unsure why this is such elusive info.

Needing this to integrate my LS motor to my factory gauges. But also as my truck was factory TBI, I'm pretty sure there was also a serial data line in the mix as well as a CEL light lead.. Would be nice to utilize it instead of running another.

Hang tight, I should be able to get you the info. Just finished up my LS into an 88' TBI squarebody a few months ago.
 

foamypirate

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Here we go. Leave both right hand sections of the bulkhead alone (shaded red and green). These are the rear lighting and head light harness. No need to touch them. The blue shaded area is the wiper wiring, no need to touch that either.

For the remaining area, you can remove everything except what is shown/described. I can't remember exactly how many wires I pulled. To remove the wire, pinch the blade together and push it back towards the wiring side. There is a slot that runs up the middle of the blades, and it will narrow when you squeeze it. Tie your fuel pump 12v+ feed from the ECM (ECM should ground a relay and provide 12v+) to the tan/white wire.

For the CEL, you need 12v+ to one side of the bulb, and the ECM grounds the other side. You should be able to use the existing cluster 12v+, and the ground wire should be in the small harness that runs across the dash and to the old TBI ECM. Brown/white wire. I tied the LS PCM ground into this wire. There is also an orange/black wire that runs in this harness. It goes to the park/neutral switch. You can tie that to your LS harness park/neutral wire, assuming you aren't using a transmission mounted neutral safety switch and associated wiring (I'm not).


Assuming you are using a 90-91' cluster for the speedometer, reference this post of mine (http://www.gmsquarebody.com/forum/showpost.php?p=301641&postcount=293) showing the 87-88' pinout, the 90-91' pinout, and a "conversion matrix". You'll want to validate the position and wire colors, but this should get you damned close.

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