82 300TD Blower Motor Not Working - PeachParts Mercedes-Benz Forum

curt5446 · #1 12-19-2013, 07:06 AM

Was on my way home the other night, with the heat on and, it got too hot inside the car so I switched off the fan. The automatic climate control does not work for some undiagnosed reason so it's either fan on or off. Drove a little further, it started getting chilly in the car and went to switch on the fan again, no dice. Fan wouldn't come one.

Thinking I had a blower motor issue, I pulled the blower motor and tested it on a battery charger. It was a little sluggish so I replaced the brushes. Spins up faster, seems to move more air. Re-install in the car, nothing. Checked the fuse, still good. Check voltage at the connector for the fan and I get 9 volts. This seems a little low.

Wondering what I can check next. The CCU is switching power to the fan (checked voltage with fan switch on and off) but it doesn't seem to be getting as much voltage as it should.

Any ideas?

Thanks,

Curt

BWhitmore · #2 12-19-2013, 11:58 AM

There is a blower motor control module behind the glove box. After pulling out the glove box you will see it mounted on a metal bracket just below the windshield. It is black in color and mounted to the far right. To the left is the HVAC controller that is silver. The black blower motor module has a plug in group of wires. I have no idea as to how to test the module other than to check for voltage. I was able to get one from a wrecked car as they are over $200 new.

Another possibility could be your ignition switch. Try to giggle your key back and forth a little and see if the blower comes on.

curt5446 · #3 12-19-2013, 12:59 PM

I will give that a whirl. Thank you!!

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curt5446 · #4 12-19-2013, 06:57 PM

Personal thanks to BWhitmore!! Found my problem. It was in the blower motor control module. Evidently the ailing brushes were creating a bit of heat and caused a solder joint to melt. Resoldered, fan working, happy camper here.

Thanks again BWhitmore!!!!