Hello all!

I have purchased an 2005 Chev 8.1L engine assembly coupled to an Allison 1000 series transmission that came out of an Kodiak chassis to transplant into our 1984 Airstream 345 motorhome. This behemoth powertrain unit came with the 3 ecu's and an aftermarket wiring harness. There was no other information supplied with the harness and I am looking for any instructions they might have for the install. The only identifier I can see on the harness is with each labelled tag, there is this funny/unique logo that is very faded on most of the labels. I have a serial number photo as well, but that doesn't identify it either. Was hoping someone may have seen or used this harness company before and can tell me who they might be? Google has not been helpful in the search.

The main things I want to know is how the gauge leads are set up and if they will run most of my analog gauges. There is a loom coming off this harness directly from the PCM. Has the CTS, OPS, Tach and Speedo lines for the gauges. The speedo line naturally has a speed signal which i will need to convert or replace my cable driven unit. There is a tach signal line, will that work with a older conventional tach? Will the temp and oil run off the other?

Any info will be helpful!!

Thank you in advance!
The harness has these circuit tags with, what I am assuming is, the brand name logo. You can see the symbol on the right of the label.

Allison behind the 8.1L

The 8.1L Chevy.

Here is the serial number tag off the harness. Is "SP" a clue?

Here is another shot of the logo.

 

It means nothing.

Show us the Harness with the computers. The Kodiaks are different from a standard 2500/3500 truck so it may have required additional wiring.

 

Throttle/pedal ECU and after market harness

PCM, TCM, T-Bore/Pedal ecu and after market harness

Pig tails for sensors

Pig tails for brake light switch and gauges

PCM

TCM

PCM

TCM

 

@1FastBrick

I had replied last week, but i don't know why my pics did not publish. Must have been too many?

I will try again with these pics. Thank you

Allison ECU

PCM

throttle pedal control unit

full harness with ECUs

PCM back side

back side of the TCU

 

It looks like it was caught in the spam filter.

On normal production 2500/3500 that appears to be 2001 stuff. It's definitely a custom harness.

Kodiaks are different animals. Unless any of the engine or transmission date codes specifically have date codes I don't believe that was from a 2005 model.

perhaps the harness was damaged and the ordered a custom made one from some one.

All the parts appear to be standard production stuff so maybe if you find and follow a 2001 or 2002 model for a 2500 with 8.1 you will find what you need.

 

The seller did originally post this setup as a 2002 in the ad. When I got there, he told me in person that it was a 2005... His wife questioned him and I just kept looking for any signs of red flags with the unit since I was already under the impression it was a turn of the century unit. On the Allison, there is a date code of 2000. I recontacted the seller, and he still contest it to be a 2005...Okay. So I think you are spot on with your evaluation of the MY.

Supposedly, the prior owner to the seller was trying to install this unit into a classic Chevelle (What the what !??!). They got the engine running but they never finished the install to drive the vehicle. They pulled the unit to go the LS route instead.

I was hoping to find out who made this harness and see if they had any instructions for the gauge side of it. Found a less, bleached tag that is almost legible, looks like "Street Performance"? If I can't identify the brand of the harness, would there be any recommendations for a harness builder of this nature I could employ to build one to suite this RV transplant with analog gauge install?



Also, who would be a good contact to reflash these ECUs to play nice with the transplant? They may have been flashed already, but it's an unknown.

Thanks a TON for the insight so far!

 

There used to be a company called Street & Performance Inc. in Mena Arkansas. But I believe they are no longer in business.

Based on the Date Code on the TCM, I would say a 2001 Model Year, The 0411 ECU was only used during 2001-2002 That electronic throttle body used is the same way.

You should be able to use a Pin out from a 2001 to find what your looking for.