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Default Root cause insight into the common BMW blower motor resistor failures


"Scott Dorsey" wrote in message
...
Bimmer Owner wrote:
On Thu, 21 Mar 2013 11:45:54 -0400, Scott Dorsey wrote:

Static resistance doesn't tell you anything, but operating current
measured with a DMM would tell you a lot.


It 'can' be done, but would require a test jig inserted inline
as the FSU is deeply ensconced under the dash while the blower motor
is even more deeply so.


I don't know the wiring diagram on that particular model, so I don't know
where you would need to break in to measure just the current of the blower
without anything else. But it does not seem terribly insurmountable,
especially seeing that BMW is very good about breaking everything out into
connectors all over.


Just measure the battery current with and without the blower running.

Turn every thing else off.


QED