Air Condition

[dand65]

I have a 1986 735i, the issue that I have is that all of a sudden the air condition does not blow thru the middle vents, I can hear the air blowing, but it's blowing to the bottom instead of the center vent, what can bew causing this issue, Thanks.

[Bear]

My guess would be the Stepper Motor mounts have failed or cracked. You have about nine stepper motors that control the dash vents (open and closed) and with age the monts may crack, jamming the motor. When you turn off the iginition did you ever hear that buzzing sound from behind the dash, that is the stepper motors reseting to their default position. Try www.bmwe32,masscom.net (this is Johan and Seans website) and it will show you a good picture of the center vent/stepper motor problem.

[dand65]

Originally Posted by Bear

My guess would be the Stepper Motor mounts have failed or cracked. You have about nine stepper motors that control the dash vents (open and closed) and with age the monts may crack, jamming the motor. When you turn off the iginition did you ever hear that buzzing sound from behind the dash, that is the stepper motors reseting to their default position. Try www.bmwe32,masscom.net (this is Johan and Seans website) and it will show you a good picture of the center vent/stepper motor problem.

Bear, Thanks for the reply, can the stpper motor cause the heating to do the same thing- , Thanks

[Bear]

Yes, the stepper motors are really devices to open or close the air distribution vents based on what you select (dash, foot,windshield, etc.)

[nael74]

i have 735 il / 1999 and the lights of a/c buttons some time not work but ac work normaly

[Bear]

Sorry, thry this:
http://www.bmwe32.masscom.net/

[Bear]

http://bmwe32.masscom.net