e30 blower motor not working on any speed

[Boris3]

Thanks. I figure the car is pissed at me for the latest track abuse.

Wondering if the connection issue is in the motor itself. I'm getting power to the switch and switch to motor.

Shot resistor or safety switch stuck open would explain the nothing on speeds 1-3.

What makes me think connection issue in the motor is the nothing on speed 4 (which bypasses the resister) unless I bridge the power and ground wires/tabs of the motor with the multimeter.

I'll try cleaning the resistor and see if that makes a difference.

[Boris3]

No difference scuffing the resister terminals. Pulled the wires off the motor and get just under 12v BU to BR. Looks like the connection issue is in the blower motor.

[Boris3]

Tried one more experiment. Tapping on the motor will get it to run for a bit at all speeds but I can see sparking inside the motor. So, my guess is something jarred loose inside the motor itself.

[straight6pwr]

aww well that sucks for the wallet, but at least you will be done with it.

[jc43089]

Brushes worn out in the motor?

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[Boris3]

Thanks. I thought about that as a possibility but in searching forums on this I don't think you can replace them on the e30.

[Boris3]

My mistake, looks like you can replace them

http://www.r3vlimited.com/board/showthread.php?t=348412

[jc43089]

They may not have a BMW replacement part but if you find one with similar dimensions. I've replaced them on an e32 blower motor, never an e30. I don't remember where I got them, maybe ace hardware. They weren't really meant to be replaced as in I had to bend some metal tabs I think and crimp the wire leads. It was a while ago though so I am not sure.

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[B C]

Yes, the hardware drawers at True Value have motor brushes

[Boris3]

Good deal, thanks for the info. Hoping to get time to pull the motor later this week and take a look to see if the brushes are the issue.

[Boris3]

Pulled the motor. The brush is worn down to about 1/16" in the housing near the + connector side, and about 1/8" on the brush in the housing near the - connector side. The sparking I was seeing when I could get the motor to run by tapping the housing was around the housing at the + connector side. With the wear in the brush the braided copper brush wire is pretty low and may be coming into contact with things it shouldn't?

[jc43089]

Yea they start much longer, excessive sparking is probably from it being so small that the connection is poor because the spring is not compressed much.

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[Boris3]

Plan B in case I screw up the brush repair this weekend or if it doesn't solve the problem (local Ace had the brushes for $4.40 each). Picked up a blower motor for $60 out of a 98 Z3 from a yard down in Kenosha this evening. Interchangeable with the e30.

[Boris3]

Nice when a backup isn't necessary.

Not the cleanest soldering job but it works

I just replaced the one brush that was sparking. The other one still had enough life left for a track car and I wanted to make sure that this was the problem. Reinstalled the motor and the blower works on all speeds.

Thanks again for the brush suggestion!

[straight6pwr]

very cool! nice tip on the z3 motor being swappable.

[jc43089]

Good deal! It's fun to repair things instead of just throw it out and spend money for a new one.

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