LS to 96+ wiring info

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DRAGGIN95

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I found this and thought it would useful
Obs to Lsx wiring made simple
Ok so if any of you guys have been keeping up with my build its been a long road. But i have found the easiest way to run the wiring for the ls engine into a 96+ Truck. This will only work in those trucks. what i have found is that you can remove the pins from your factory harness and install them right into the ls harness and pcm. that way you will be using the OBS fuel pump relay, VSS signal, Check Engine light, and brake signal.

basically if you decide to do your own harness or have one made you will remove from the green connector completely

9 - Fuel Pump

46-Check Engine

16-4wd low (4wd only)

blue connector

33- brake signal

then from your stock obs harness you will remove the following pins and insert them directly into the ls harness

Black connector plug

1 fuel pump

5 Check engine

10 Brake signal

23 4wd low (4wd only)

this saves you from having to cust and splice wires and makes for a seamless integration. as far as the starter you can reuse the factory PNS switch and obs solenoid wire which should be purple.

the other connections from the harness like ignition and constant power should be pretty straight forward.​

 

DRAGGIN95

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Yeah or a modded truck ls harness, these could also be added to an aftermarket harness such as a nelson harness for a more oe look.
 

1996*GMC*SHORTBED

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Good info. Speaking of the PNS switch on a '96(& up) pickup, where is it? And is one needed to make the inside column indicator light up & work? Wire color? thanks
 

95SUBURBANLM7

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So if I'm reading this correctly, and Id like to think I am, it looks like it is much easier to swap an LS into a '96+ GMT400. I really wish I had seen this before I spent the time to mod my '95 harness. With that said, how doable is swapping a '96+ harness into my '95? I know the C100 is the same, so its just a matter of repining it. Right?

Any help would be appreciated.
 
Last edited:

Epicsniper145

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What about all the other guages can you do the same thing. Oil pressure voltage engine temp stuff like that. Or how does that stuff work
 

Alonso

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This is great information! Exactly what I need just for ls1b (blue/red) pcm pin outs. Any help would be muchly appreciated. Thanks in advance.
I found this and thought it would useful
Obs to Lsx wiring made simple
Ok so if any of you guys have been keeping up with my build its been a long road. But i have found the easiest way to run the wiring for the ls engine into a 96+ Truck. This will only work in those trucks. what i have found is that you can remove the pins from your factory harness and install them right into the ls harness and pcm. that way you will be using the OBS fuel pump relay, VSS signal, Check Engine light, and brake signal.

basically if you decide to do your own harness or have one made you will remove from the green connector completely

9 - Fuel Pump

46-Check Engine

16-4wd low (4wd only)

blue connector

33- brake signal

then from your stock obs harness you will remove the following pins and insert them directly into the ls harness

Black connector plug

1 fuel pump

5 Check engine

10 Brake signal

23 4wd low (4wd only)

this saves you from having to cust and splice wires and makes for a seamless integration. as far as the starter you can reuse the factory PNS switch and obs solenoid wire which should be purple.

the other connections from the harness like ignition and constant power should be pretty straight forward.​

I found this and thought it would useful
Obs to Lsx wiring made simple
Ok so if any of you guys have been keeping up with my build its been a long road. But i have found the easiest way to run the wiring for the ls engine into a 96+ Truck. This will only work in those trucks. what i have found is that you can remove the pins from your factory harness and install them right into the ls harness and pcm. that way you will be using the OBS fuel pump relay, VSS signal, Check Engine light, and brake signal.

basically if you decide to do your own harness or have one made you will remove from the green connector completely

9 - Fuel Pump

46-Check Engine

16-4wd low (4wd only)

blue connector

33- brake signal

then from your stock obs harness you will remove the following pins and insert them directly into the ls harness

Black connector plug

1 fuel pump

5 Check engine

10 Brake signal

23 4wd low (4wd only)

this saves you from having to cust and splice wires and makes for a seamless integration. as far as the starter you can reuse the factory PNS switch and obs solenoid wire which should be purple.

the other connections from the harness like ignition and constant power should be pretty straight forward.​

I found this and thought it would useful
Obs to Lsx wiring made simple
Ok so if any of you guys have been keeping up with my build its been a long road. But i have found the easiest way to run the wiring for the ls engine into a 96+ Truck. This will only work in those trucks. what i have found is that you can remove the pins from your factory harness and install them right into the ls harness and pcm. that way you will be using the OBS fuel pump relay, VSS signal, Check Engine light, and brake signal.

basically if you decide to do your own harness or have one made you will remove from the green connector completely

9 - Fuel Pump

46-Check Engine

16-4wd low (4wd only)

blue connector

33- brake signal

then from your stock obs harness you will remove the following pins and insert them directly into the ls harness

Black connector plug

1 fuel pump

5 Check engine

10 Brake signal

23 4wd low (4wd only)

this saves you from having to cust and splice wires and makes for a seamless integration. as far as the starter you can reuse the factory PNS switch and obs solenoid wire which should be purple.

the other connections from the harness like ignition and constant power should be pretty straight forward.​


The ls1b pcm connectors wouldn't be same as green and blue?
I found this and thought it would useful
Obs to Lsx wiring made simple
Ok so if any of you guys have been keeping up with my build its been a long road. But i have found the easiest way to run the wiring for the ls engine into a 96+ Truck. This will only work in those trucks. what i have found is that you can remove the pins from your factory harness and install them right into the ls harness and pcm. that way you will be using the OBS fuel pump relay, VSS signal, Check Engine light, and brake signal.

basically if you decide to do your own harness or have one made you will remove from the green connector completely

9 - Fuel Pump

46-Check Engine

16-4wd low (4wd only)

blue connector

33- brake signal

then from your stock obs harness you will remove the following pins and insert them directly into the ls harness

Black connector plug

1 fuel pump

5 Check engine

10 Brake signal

23 4wd low (4wd only)

this saves you from having to cust and splice wires and makes for a seamless integration. as far as the starter you can reuse the factory PNS switch and obs solenoid wire which should be purple.

the other connections from the harness like ignition and constant power should be pretty straight forward.​

 
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