Quote Originally Posted by Frank87 View Post
Before:
- experimented with a spare IHKA computer( the one with the 3 colored connectors). Same problem.
- removed the auc sensor and module just in case. Same problem.

Update to this thread:
- I have replaced the DME, no change
- I have replaced the Check Control Module, no change
- I have replaced the A/C control panel with an identical one, no change
- I have replaced the 3 buttons defrost/AC/AUC panel, no change

Problem still remain:
- cold air doesnt work whether A/C button is on or off. IHKA blows hot only
- A/C doesnt work, there is no way to get the compressor going. System is leak free and full. All wiring resoldered where needed
- rear window defroster does not work at all
- check control on the instrument panel does not work. Bottom bar does not light up and if you shine with a light it says "Check Control, Betriebsanleitung"

I have a total IHKA rebuilt. Going to swap it in a month or 2. Meanwhile I keep checking the electronics as I work on the car.
Jump the hot lead to the compressor and watch it work. If not then you can trace it. If it works you can trace it. Not sure if I am missing a whole lot here just reading along.