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Gen 4 swap AC

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Old Aug 5, 2023 | 09:06 PM
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Question Gen 4 swap AC

Hey All!!! I did a 6.2L Gen4 6L80 swap into a 1999 Tahoe. I have the truck running on the donor harness. Now I need to get things like the AC functioning. Anyone know how I should go about doing this? The donor harness has the AC wires in the harness still and I still have the AC wires from the 99 harness. I was thinking of using 99 wires, but not sure how I should go about doing this. There doesn't seem to be a lot of info on the Gen4 swaps out there.
I'm sure someone has done this in the past.
TIA
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Old Aug 5, 2023 | 10:58 PM
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I'm not sure if there's a difference beside the 3 pin pressure plug if you need to find it hopefully you don't have too many left over and you can trace it with a multimeter. If I had to guess it's ground positive and a signal wire.The clutch should be 2 wires I think it's ok to reverse polarize it so locating it is all for that one but don't quote me on that look at the plug on both sides on both and see if it has a orientation tab of some sort I don't think it does.

https://www.2carpros.com/questions/a...witch-16980287

This may help you. People are very helpful here with the right questions and photos or info of what you specifically don't understand help alot.
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Old Aug 19, 2023 | 01:58 PM
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Only the p01 and p59 ECU's can run the A/C with a physical signal wire rather than can messages from the BCM. On a gen4 you will have to use the 99 Tahoe A/C wiring
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Old Aug 19, 2023 | 02:55 PM
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Can't the pins be tapped off the ECU and tuned in?

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Old Aug 20, 2023 | 09:16 AM
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The ECU can turn on the compressor but you can't request the compressor to be on with a simple wire. Only with class 2 serial/canbus commands.
The physical inputs don't exist
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