So my AC has a mind of its own and wanted some advice on what to check in order to fix it. It does work but only in the morning time when it is cool. The fans and compressor come on normally but only for a few minutes. After that I get nothing. The recirculation button doesn't light up after the unit stops working. My mechanic thinks the controller unit is bad which is possible but I wanted to get your guys take on it. Should I check the ac relay and thermostat which are cheaper fixes or should I go ahead and bite the bullet and replace the controller unit.

 

Fuse #1 controls the front blower motors and the CCU. I would start there. Also check out Tor's website. he has a comprehensive checklist for our A/C

https://www.bergvillfx.com/categorie...system-details

 

There is no need for replacing the Climate Control Unit, a repair is much more affordable, if needed at all. Did your mechanic check the power supply lines to the unit? They are described in the link above.
When you state that you get nothing when the unit fails, what do you mean? This is important in order to find the fault.
Is it only the fans that stops, (and the light in the recirc button as you describe) or will the unit move the HVAC servo motors when you move the two slider and the temperature *****? If it does, I expect that this is a fault with something else than the unit itself.
All the best,
Tore

 

Thanks for the replies. To clarify when the unit fails, nothing happens. Fans cut off, recirc light cuts off, no servo controls.

 

Then the CCU has an intermittent connection internally. Read here under Porsche, CCU 964/993; https://www.systemsc.com/problems.htm