AC Controller issues???
 

My wife and her 323i are having some issues which are now my issues.
It appears that when the front radiator fan (electric) is on the air conditioning control system is not operational.

it would almost seem like there is a power short as the control unit dims and the buttons are useless.

when the front fan is off the ac controller works perfectly.


Any Help????


Mike

Sorry, the car is a 1999 year.

The front fan can be triggered by either a temperature switch in the side of the radiator OR it is turned on when the AC compressor is on. Either way it is turned on by a relay.

Maybe the fan running is a symptom and not the cause of your issue. In other words the problem may be with the AC control unit shorting and turning on the fan for no reason.

Try to download the electrical troubleshooting manual and you will see the radiator fan and A/C compressor logic of operation. Without the schematics, everything will be a guess.

The only common item between the fan relay and compressor controls is the diode.
Check the diode just to make sure it is only passing voltage in one direction.

http://forums.pelicanparts.com/uploa...1255391787.jpg