Another AT545 to A2000 Tranny Swap

[Diverdude0075]

Correction

It was wire 13J not 13E.

 

[IndianaSchoolie]

This thread seems to say with a factory harness I don't really need to connect anything to the motor other than a TPS, am I oversimplifying this?

https://www.dieseltruckresource.com...discussion-92/thinking-allisons-266786/page2/

 

[Booyah45828]

This thread seems to say with a factory harness I don't really need to connect anything to the motor other than a TPS, am I oversimplifying this?

https://www.dieseltruckresource.com...discussion-92/thinking-allisons-266786/page2/

You need to understand that the term factory harness isn't really anything specific. It's just a harness from the factory, and allison used a boat load of different harnesses depending on the application. The guy in that link used a harness/trans from an 8.1/allison out of a 1 ton, and that is a rare combo to come across. GM made a boat load more trucks with the 6.0 and diesel then they did with the 8.1.

The reason that guy used and 8.1 allison over any of the others is because the 8.1 allison used a tps input, whereas most allisons gleaned that information off a can bus between the ecm and tcm. Christopher tried doing that with his IIRC, but ran into issues when cruise control was being used, and switched over to pulling load from the j1939 circuit.

Also, again iirc, the tps input isn't a voltage/resistance based potentiometer, but a pwm based signal, which requires a different and more expensive tps compared to most commonly used tps.