Hi everyone! I’m new to this forum but I’ve been in the auto industry for years and have done ls swaps before. I have not done a 4x4 yet and am about halfway through my first one. We are utilizing the stock transfer case which is the push button NP8 tc and am having some trouble getting a straight answer with wiring. My standalone engine harness is complete but I’d like to make my tc/4wd harness standalone also. I have my control module, switch and stock harness, does anyone know a good reference or guide with the 4wd stock tc wiring? I’d like to put power too it and have it shifting before I drop in the motor to save time and energy rather than crawling underneath. Motor is a 99 lm7 4l60 stock tc dropping into a 1979 bronco

 

First, WELCOME to the forum.
While I personally cannot help you with your question, I am confident that someone here will be able to help.

I always suggest that (new) members update their Profile to indicate in which city and state they live. It is not uncommon for a nearby member to then offer personal help.

 

Okay, I will do that! I sure hope somebody is able to help, I know there is a company selling standalone transfer case harnesses but I can’t bring myself to pay 600 dollars when I have the harness in front of me and just need to know which wires need to be sent to a relay, power, gnd, etc.

 

The GM SPO database shows that the RPO: NP8 is the New Venture Gear/ New Process Gear transfer-case model: 246GM/ 246-C.

While the 246GM transfer-cases have mostly remained the same through out their production run...
There were 4 reversions to the unit internally and many more in terms of control/ electronics.
The wiring varied some between vehicles and years of production.

I need to know what vehicle the unit originally came from to find out which encoder-motor, sensors, electronic transfer-case shift control module, and wiring harness was used for your vehicle.

Here is a link to an AutoZone on-line repair guide...
It shows generic wiring diagrams for the 243 and 246 transfer-cases.

LINK

If the original vehicle was a 1999 C/K truck... Just post which one specifically it was.
The GM SPO repair database only goes back 10 years... but the engineering database goes 20.
I have a bad feeling we will have just missed out on being with in the cutoff.

 

Did you check the electrical diagrams in the link that Vorteciroc listed?
I didn't know that Autozone had those; that is pretty nice. Professional mechanics generally have access to even more detailed electrical diagrams as part of their "Mitchell1" subscription but those are only available to paying customers. I'll be happy to screen capture a few of those diagrams for you if/when we determine exactly what you have.

 

I did, I saved all of them and will try to go over them they’re just a little hard to follow. I have a pending post on this thread with some pictures of what I’m dealing with to give everyone a better idea of what I’m talking about. It was running and driving before pulling and have put power too it and had it shift (from what it sounds like) to 4 hi from 2wd but 4 hi flashes constantly and 4 lo I could hear no shift in the transfer case and also a constant flashing in the switch. When I manually shift the transmission into park or neutral I also see no neutral light. I have a feeling some wires will have to go to an added relay and maybe a closed loop with a resistor? Especially since I will have no front axle actuator that the original donor vehicle had

 

Hey I know this is an older post but I'm in search of the same info and I can't seem to find anything. Did you ever figure out out?