95 GMC C1500 with L29 454 and 4l80e

DonF said:

Thanks, but 95 and up had air bags. I would rather put an early wheel on it if I can find one in good shape. I like the look better and my airbag wire is already removed.

Click to expand...

You don't have to hook up the airbag ya know, in fact the 2500+ trucks never got them in the first place. But if the early wheel tickles your fancy better, I get that. The columns are different and I'm not sure about the splined bit at the top. I know on your style column the splined upper bit can be swapped out to accommodate newer wheels, so maybe you could go the other way to fit the older wheel if it doesn't drop right in.

The wiring is a mess! I can fix it but I need to find a good wiring diagram for the 1995 year c1500. They took a painless wiring L29 harness and tried to hack it into the 95 harness. The Painless harness is pretty well documented by color and location. The fix is to strip out all both harnesses and reinstall properly. I have a 88-98 Haynes manual but the wiring info is not detailed enough. I also have GMs ESI software, but its a mid 2000s copy, and doesn't seem to have anything other than tsb's and some basic engine and trans info for 1995. I need to be able to pin point most wires in the engine harness by connector and color. That way I know what can be stripped out and what has to stay. Is something like Alldata DIY detailed enough wiring wise? I would be willing to spend the subscription fee to make this come out nice.

Have you checked the '95 factory service manuals? You can download them as PDFs here for free.

https://www.gmt400.com/threads/88-95-service-manuals.43575/

No I didnt know it was that easy, Thank you!

No problem! Hope you find what you need in there.

I finally started working on this the last few weekends. The painless (painful) l29 swap harness is now removed and the factory harness is pretty hacked up too. I have a lead on another uncut 95 harness to start fresh and combine with the reworked swap harness. I ordered a 2002 Express van pcm that's here now. Has anyone stuffed that ls style pcm in the corner under the dash where the 1995 silver tbi box went? I would rather spend the time putting the new ecm under the dash for a cleaner under hood area. I also took out the abs module for the same reason. The older proportioning valve and a few new brake lines should make that complete. The rusty brake booster will meet the bead blaster before the project gets too far along.

The PCM pins are most likely different on the 95 and won't just snap in to the 411 connectors.

Yes, this is not a "snap together" job. That's a minor hurdle.

The painless l29 swap harness and the hacked up 95 engine harness are removed from the truck. The rectangle passthrough hole under the coolant bottle, the stuff inside the plastic housing is tough. I dont think its RTV, more like some specialty glue to bed the wires. I was able to carefully remove the plastic housing with a lot of work, but the comb used to separate the wires inside the mess is not salvageable. Are they available bare? Not likely and not very important. I just figured with all the OBS LSx swaps, someone had to take that part of the OEM harness apart. I would rather run whatever engine control wires that I do use though that hole just to keep it clean.

The more I look, the more hokey stuff I find. The shifter linkage is from a van (so was the 454 engine and trans). The cable comes out from the firewall and the cable gets all turned around to end up where its supposed to go. I saw on youtube where its supposed to route in the trans tunnel. The truck was originally a manual trans v6 so there is no hole in the tunnel for the shifter cable to pass. Cutting isn't a problem, I just wanted to make sure the factory opening didnt have a flange or something that would complicate the sealing of the hole with the factory grommet once its cut. I am sure there have been some manual to auto conversions here, just didn't find much on making the cable hole itself.