E38 740i Fan Question

[joshblues21]

This is regarding the pusher fan... on a E38 740I 4.4l
I know vw/audi not bmw but I told a friend I would take a gander...

I realize these fans are supposed to cool even after the car is off, but the fan is on all the time no matter what, even if the key is off, the car is cold, etc.

After some gandering, I supposed that the source of the problem is some sort of module on the back of the fan that connects the control and +12v wires...

So to dublé check...

Is it true that: pusher fan gets 12vdc constant? And ecu control wire turns on the fan? The little black module on the back of the fan acts as a pilot relay of some sort?

TIA and sorry for the lack of pics

[1965truckrod]

The Pusher fan should be running when the A/C Compressor is engaged and when the heat is over a certain temperature, usually when the clutch on the manual fan engages as well. If the fan is running all the time to a point where it drains the battery dead then chances are they temperature sensor has gone bad. Check out this forum and see if they have a common fix. Its a bit of work to replace the fan itself but hopefully its just a normal thing. I know my push fan runs for a while after the car shuts off until the car has cooled enough.

http://forums.bimmerforums.com/forum...play.php?f=310

Jesse

[mike]

Fan is bad, there was a recall on those, they have a been known to catch fire and burn down garages. IIRC its constant power and ground but receives a duty cycle signal over the third wire. Usually they fail to inop.

[joshblues21]

Thanks mike & jesse, ill check it out and tell my bud to take it in and check the recalls. Thanks again guys