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Blower Control Repair w/ pics!

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Posts: 49
Joined: Sun Mar 09, 2014 4:19 am
Location: DFW (Plano) Texas

Re: Blower Control Repair w/ pics!

Post by JoelR » Sat Jan 18, 2020 8:53 pm

So my heater fan stopped blowing at any setting, but the A/C fan worked fine for all settings. I replaced the transistor by the heater fan with the 2N3771, and the fan started working, but only on high. It did this a few times, then it quit working altogether. The A/C fan is still working fine.

The heater fan was not making any bearing noises. I could rotate it by hand, and it was a little stiff, but I don't have any reference to compare it to in order to know if this is normal or if it has too much resistance.

I have not torn into the dash controls yet because the A/C fan is operating normally, so I tend to think the potentiometer and the transistor in there are OK.

Is there any reason to suspect the dash controls, or should I suspect the fan motor?
1983 633CSi 5-speed Black & Tan
2008 X5 4.8i
2004 MINI Cooper S 6-speed
2001 Z3 3.0i 5-speed
DFW Texas

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