Wiring harness swap from 6.5 to 5.7

[jlake97]

Hey all, i have a 96 k3500 that had a blown 6.5 in it and i am swapping in a 350 out of a 96 Tahoe. I have a Nv4500 out of a 2000 k 2500 that was bolted up to a 350 that i will be putting in this truck as well. I took almost the entire wiring harness out of a junkyard 96 k1500 truck ( computers, fuseboxes, interior and engine bay, cluster, security module by key). I guess to start im wondering if i could get away with just swapping the portion of the wiring harness in the engine bay/ outter firewall with minor modifications, or if i do in fact have to do the entire harness under the dash as well. Also would love access to wiring diagrams, any help with this or other tips for this project would be greatly appreciated!!

 

[GoToGuy]

The first thing I would do is download the OE service manuals for year 96 and the diesel and unit repair if available. In a sticky above link to pdf. They have the electric diagrams, so you'll have road map for the wiring. You realize this is a big job to correctly and be able to diagnose issues in the future. If you wish to avoid or have less cut and splice at the beginning of electric chapter is info on removing pins in connectors to change or reposition them. This is what will help and are in service manuals.

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[GM Guy]

is the 6.5 wiring for an automatic or manual?

 

[99xcss4]

I am in the middle of a diesel to gas swap on obd1 I started with the engine and transmission harness I had to get the interior harness and the rear harness for the fuel pump I have not had time to finish the swap sadly I hope I have every thing I need

seeing as you are obd2 I do not know if you will need to swap your interior harness or not you will need to change your rear harness for the fuel pump

note when I say rear harness I amp talking about the tail light harness it has the fuel pump wires in it on a gas truck on a diesel it has the wires for the fuel gauge only

 

[jlake97]

is the 6.5 wiring for an automatic or manual?

Both harnesses i have are for automatic, i am aware that i will probably need to make some adaptations to the harness for the speed sensor setup on the nv4500/ transfer case

 

[jlake97]

The first thing I would do is download the OE service manuals for year 96 and the diesel and unit repair if available. In a sticky above link to pdf. They have the electric diagrams, so you'll have road map for the wiring. You realize this is a big job to correctly and be able to diagnose issues in the future. If you wish to avoid or have less cut and splice at the beginning of electric chapter is info on removing pins in connectors to change or reposition them. This is what will help and are in service manuals.

You must be registered for see images attach

I will try to locate these manuals, I've started looking for diagrams and haven’t had luck yet

 

[xXxPARAGONxXx]

I will try to locate these manuals, I've started looking for diagrams and haven’t had luck yet

88-98 Service Manuals

Bought a 96 service manual on a cd, and uploaded it to my computer there are 2 books with a combined storage of 750MB. I took a quick gander through the pages on the forum, and haven't seen a service manual for the 96. how and where do I upload the book 1 and 2 pdf files to help out for 96'ers...

www.gmt400.com

 

[GoToGuy]

At the top of the forum is a sticky thread with the PDF links to all the OE service and unit repair manuals. All the info is in them, including wire diagrams.