heater function after a swap

[piper6909]

Originally Posted by Stl-986

The AC just gets a signal (voltage) to turn on or off, there is no feedback to anything. There is just 1 wire that goes to the AC.

Of course the above is for a car that isn't CAN based. Dont think even a car with CAN will know if it's on or off, but I'm not 100%.

also helps to know the year, put it in your signature.

The DME has to know that the compressor is on, so it bumps the RPM up at idle to prevent stalling.

To Outside's issue, I don't think having the AC compressor in or out should effect your heater functions. I think you're going down the wrong rabbit hole there. Unfortunately, I don't have the knowledge to show you the right path, sorry.

https://rennlist.com/forums/924-931-944-951-968-forum/312073-help-ac-compressor-wiring-question.html

Scroll down to post #5 for A/C wiring diagram.

It looks like as long as the low pressure switch is closed, which yours obviously isn't since there's no freon charge, then voltage is sent to the compressor AND the DME.

But again, it should have no effect on your heater functions.