5-Series (E12,E28, E34, E39, E60)Chat relating to the BMW 5-Series of all generations. Specific models include: BMW 518, BMW 520, BMW 520i, BMW 530i, BMW 528i, BMW 530i, BMW 518i, BMW 524d, BMW 525i, BMW 525e, BMW 528e, BMW 540i, BMW 535i, BMW 520d, BMW 525td, BMW 525d, BMW 530d, BMW 525i/xi, BMW 530i/xi. (BMW 5-Series Forum)
As I sat in my car pondering the drive shaft repair I just went through...enjoying the peace and quiet...I happened to notice a very low pitch electrical motor running that I could hear near the center of the dash. It is very faint and sounds like the CD drive motor is running. I had a CD in the tray and removed it, but no difference.
Also in the vicinity are some small vents under the CD player that I think are for the automatic climate control sensors. Could there be a fan motor associated with that function?
I know from the forum (thank you all so much!) that lots of things continue to "stay on" for at least 16 minutes after the car is turned off, so I locked the car up and came back about an hour later. When I unlocked the car and got in, the mystery motor was still running.
Now it may have turned off, I don't know really know, but the car has central locking so everything lights up when the car is unlocked and perhaps that started the motor again....I'm just guessing.
Does anyone have any idea what this might be??
As always, any insight would be greatly appreciated!!
I will tell you this same thing happen to me in my e36......if you turn the key on it, it will go on, so that is exactly what I did, after I turned the key on & off a few times, I figured it was on a timer, sooo I turned the key off & sat in my car until it went off.....& it did turn off, in I guess about 5 minutes or so....although sometimes it seemed longer......
Interesting... Am I correct in assuming that just opening the door sort of "wakes up" the car, turns on the HVAC system and starts this motor running?
Yes. What you're hearing is the air sampling fan. It draws air over the climate control sensor. The fan stays on for 16min after you shut off the ignition, and turns on as soon as you unlock the car. That's why everybody thinks it's on all the time. If it gets annoyingly loud, you can clean it. Quoted from another forum:
1. remove cupholders 2 screws behind each cupholder ( you can go thru stereo as well)
2. then reach behind and push climate control outward its just two metal clips holding it in
3. once you have it out pull off your wiring harness to the climate control
4. once you have your climate control disconnected seperate the front of your climate control from the back housing (little plastic clips use a flat head screw driver may help)
5.after you have it separated slide the circuit board out
6. when you have the circuit board out youll see where the fan is and how dirty it is the fan will actually slid rite off if you pull it upward
Thanks! My 525 had the same problem I just cleaned the sampling fan to quiet it. Last week the right front wheel damaged the inner wheel-well and also the ambient outside air temp sending unit. It appears the Sampling fan has been on ever since. Does the sampling fan work with the outside air temp sending unit? If so that would explain the dead battery this morning!
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