BMW Repair: Dual climate control a/c module 88 735i blows only hot air from most of the fronte a/c vents., dual climate, loose ground

Question
Emanuel,
Could this be a relay problem, a loose ground, or could the electronic module be carbon tracked or dust tracked?
My mechanic wants to replace the $400 a/c module.
It started this problem intermittently at first with various ones of the front a/c vents at different times. The rear vents always blow cold. The compressor has been serviced.
Have you ever seen this problem beforE  -Andrew  

Answer
is yours a digital or analog setup...the digital ones are really tricky, the anoalog ones have cables that mechanically open and close the vents, it could be possible that the cable is stuck in the "heat" on possition...if its digital i wouldnt advise you to mess with it... its a headache... if its analog... open it up trace the cables see how it works (or should work) find the problem...and save some money.

Hope this helps.

manu