Blower Motor Control Module Bypass (or replacement source)

[urq]

I usually go for the simplest solution ... so I'd say hard wire the thing for the trip home.  Selecting a resistor to throttle the speed would be a crap shoot, and you might choose a resistor that couldn't handle the power dissipation and fail on the way home.  
 
In all my experience with T44/V8s I've only had to replace one CC motor controller, so the fact that yours has failed twice in two years causes suspicion to me.  When you get home, I'd recommend investigating whether or not the climate control itself is flaky and that is making you think the motor controller is bad.
 
Have a safe trip!
 
Steve Buchholz 

________________________________
 From: mboucher
 Sent: Thursday, December 26, 2013 5:40 AM
Subject: Blower Motor Control Module Bypass (or replacement source)
 
My blower motor control module went out for the second time
in two years.  Followed the diagnostics
that confirm it’s the module, not the motor (when you jumper two of the cables in the control module, motor runs at high speed).

I’m out of town (in Toronto) and haven’t been able to source
a local replacement for less that $250. 
I’m wondering about various options for a temporary fix to get home and
allow time to shop around for a better price.

1.)  
Hard wiring the blower for the 6 hour drive back
to Montreal (ie jumper the power cable in and out of the control module).  The blower will run on full
speed which will be noisy but that’s the only downside I see.  I measured the current draw and its 10.5
amps.   With a healthy battery,
alternator, and mostly highway driving, I don’t see a problem electrically

2.)  
Same as above, but running the blower through a low
resistance high capacity resistor that  could pick up at an electronics store, which might
bring it down to medium speed for drive. 


3.)  
Same as 2, but I read about using a common
household object with low resistance, say a 100watt lightbulb, which could both
stand the power without overheating, and would limit the total current draw.

4.)  
Running a wire into the car and using a toggle
switch to turn fan on/off.  Don’t so much
like this option for the risk of the 12V live contacting ground, although
I know there’s a 30A fuse for the blower motor.

Thanks for any thoughts.

MC

                          
_______________________________________________
quattro mailing list
http://www.audifans.com/mailman/listinfo/quattro
http://www.audifans.com/kb/List_information