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Old 08-16-2009, 06:36 AM
cn90 cn90 is offline
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Location: Omaha NE
Join Date: Mar 2006
Posts: 14,979
Mein Auto: 1998 528i 5-sp 140K+
1. FSR: unlikely because you just changed it, but there are people with FSR problem straight out of the box, especially non-dealer part.
Make sure yours is BMW FSR.

2. Blower Motor itself.
Instead of tearing the dash apart just to look at the Blower Motor, study this diagram:

And this diagram:

On the FSR Connector itself, pins #1 and #5 feed the Blower Motor.
Apply 12 V to #1 and #5 terminals and the Blower should run, if not Blower Motor is bad.
(In BMW terminology 31 is usually ground, 15 is positive feed. So ground goes to SW/GN wire, and positive goes to RT/GN wire).

To be certain that 31 (or terminal 1 on the connector) is ground, using a Digital Volt Meter (a few dollars at Harbor Freight), select Ohm-meter setting, connect terminal 1 on the connector and the chassis, it should read 0 ohm.

Also, check if terminal 2 (Fuse 76 circuit) has 12 V when the HVAC button is switched on.

If you solve this problem, then congrats, you are now formally a BMW master electrician hehe!


PS: Make sure you don't have a bad fuse: a bad fuse can either fail completely or fail intermittently. Remove the fuse, check and re-insert it.
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