View Full Version : E39 Heater not working at idle

Dado 540
11-12-2008, 05:12 PM
Hope to resolve this annoying issue i've had for some time now.

In the summer very hot heat is comming out of the vents regardles what dial the teperature is on. Once i start the A/C the heat stops and cool air comes out ONLY throught the upper vents. if i select to blow into feet it STILL BLOWS VERRRY HOT. When i turn off the a/c heat is still there just not and hot. Basicaly i cant have any cool air in my feet.

In the winter now, there is no heat while im stopped/at idle unless im driving. When driving the heat is very hot. Again the dials are at 16 dergees celsius. It seems as if they are not working, regardless of what temperature i set.

One more thing. When it rains my windows start to fog up like crazy. As soon as i turn on the a/c the fog is gone. as soon as i turn it off with in a minute it fogs up again. i hope it doesnt rain when it cold out, cause i gotta drive with the a/c on! ahhh

AND...when i open any of the windows or moonroof the air seems to be blowing harder regardles of the set speed of the fan. Wierd! but it doesnt happen when a/c in on.

I've done some research, they seem to be pointing to the thermostat, maybe final stage unit....i donno.... need some expert max members input!!!!

any input is greatly appreciated

11-12-2008, 05:34 PM
Dado, we addressed this in another thread....the stepper motors that control the air flappers are out of synch. The control unit needs to be reset to factory specs for them to direct the air properly.

Dado 540
11-12-2008, 06:30 PM
MLue you are right sir. I knew i mentioned it before just couldt find the thread. Thanks!