92 735I A/C info needed - United Bimmer Community

**higgdann735i** · 05-07-2007, 07:09 PM

I have a 1992 BMW 735I. Was blowing cold up to 2 weeks ago. I was driving and all the sudden stopped blowing cold and started blowing warm but not hot. I check the Compressor and working fine, I check the 134A and show about 6 lbs, in the safe side. What could be the Problem? Is it a temperature sensor. The gauge tells me the out side temp. The heat blows when I adjust the temp up to 71 or more. all the motors. seem to be working when I test them. Any subjections? let me know please
Thanks

**c1apton** · 05-07-2007, 08:38 PM

the receiver/drier is probably clogged up. (It was common in early 134 AC units) You have to replace it and recharge the system.

**higgdann735i** · 05-09-2007, 08:56 PM

I replaced the dryer, and charged the system. Still the A/C blows warm. Is there a sensor or some control that is not allowing it to come on. I Hear the cluck clicking on when turn the AC on, the compress work, There is 3 lbs of pressure. Any more idea's. It is getting hot here in california so I need the A/C. Is there a switch that may have gone bad? or what about the on board Climate control computer? Any idea please offer, I am all ears....

**c1apton** · 05-09-2007, 09:19 PM

the expansion valve has a sensor built into it.At this point IMO I would take it to the dealer or AC specialist... it may be a little costly but they have diagnostic equipment instead of throwing parts & freon at it. 1 more question, when was the last time you changed the cabin micro-filter? A clogged microfilter would block air from flowing over AC control module & evaporator.

**higgdann735i** · 05-09-2007, 11:12 PM

I will check the cabin filter first. The last time changed was about 3 years ago. I think I have ruled out Control Module being bad, only Thing left would be, Expansion valve, cabin temp. Thanks so much for the info. I will let you know what happens