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Suburban and SUV Discussion of Diesel Installed SUV's

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  Topic Review (Newest First)
04-19-2018 08:55 AM
05DenaliLLY Also did you check the cigarette lighter fuse? That was blown on my Denali when I bought it and nothing would communicate via OBD port because of it.
04-19-2018 08:51 AM
05DenaliLLY Which BCM did you use?
09-13-2017 09:11 PM
Denali Build

I am new here and am hoping to find some help with this build. First, here is what I am working with:

2004 Yukon XL Denali on 2002 Suburban frame 04 body harness retained - utilized 2002 tank setup.
2004.5 LLY motor with Allison transmission and all wiring/drivetrain computers- this had bad head gaskets when we got it, but it did run and drive. Engine has been completely rebuilt before going in the Denali.
2002 t-case and all wiring up to the buttons in the dash.

This has been the longest project in the history of ever. If it could go wrong, it probably has. Took the motor out last November and started the long arduous task of swapping the frame and getting the LLY ready to roll. What we believed to be bad head gaskets turned into a full out engine rebuild. Whoops. Move to present and I believe I have constant power to all the circuits that should have power. (My understanding from putting the 6.0 into my Jeep as a standalone system, is that all orange wires should have constant power, while pink wires are keyed power.) When I hook up the batteries, the ABS module makes constant noise, it will not shut off. The only thing happening on the dash is the check engine light and both turn signals stay illuminated. There is no security light that comes on, it is ONLY these three lights on the dash. This happens with key on or off, the check engine light simply gets brighter with the key on. No dome lights, nothing inside turns on. I have tried the fuse box out of our other LLY pickup (not the donor, this is a driver), and it does the same thing. If I plug EFI live in, it says no vehicle detected. I have tried the Denali cluster as well as the donor cluster, no difference.

I have added/changed the following wires:

Added blue wire from C100 to cluster for wts
Added yellow wire from C100 to SP205
Changed and added wires for the fuel sending units to C152
Swapped out the ABS module from the 2004 LLY pickup and repinned those wires exactly as they were in the donor

There is no security light when batteries are connected, regardless of which cluster or fuse box I use, and no interior functions work. ABS module runs regardless. I am fully aware of the limitations using the 02 stuff from the tanks and 4x4, but neither of those things should prevent it from starting. Where do I go from this point?

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