W126 Blower Motor Questions - PeachParts Mercedes-Benz Forum

#1 08-08-2003, 12:15 PM

The blower on my 1983 300sd will sometimes totally stop blowing. It happens only occasionally but, in the South's summer heat, it is very annoying. One thing leads me to believe that it may be the blower motor rather than the climate control unit. After it stops, it sometimes starts again spontaneously after hitting a bump in the road. I'm thinking bad bearings or brushes (or both) may be causing the motor to seize. Also, the output of the blower, even when it is running is pretty dismal. It's barely enough to keep the passenger compartment comfortable in the summer. So, I suppose my questions are... Does it seem like a blower motor problem? Is it hard to remove and replace? Is it rebuildable? Is there a higher output version available or can this one be modified to move more air?

Thanks.

surfblau · #2 08-08-2003, 01:42 PM

I am basically having the same problem.

Last year, I had exactly the same problem as you describe. Kicking it also worked, but a bump in the road did too. So I opened the blower motor up.

The brushes on mine were very short and only weakly contacting the copper shaft of the motor. I replaced with vacuum cleaner brushes, but my fix is no longer working...darn, but no real surprise (I opened it again last week and noticed a broken brush wire, I resoldered, but it stopped working again).

So I am biting the bullet and buying a new blower motor. +/- $100 seems fair for a part that basically lasts 20 years. Getting the fan to attach to the motor looks interesting.

alec

sixto · #3 08-08-2003, 02:58 PM

Mark the point along the motor shaft that's exposed under the fan cage. Try to set the cage on the new motor in the same position so the cage doesn't scrape the blower housing.

If you have access to a press or if you can get creative with a jack, it's better to press the motor off the cage than to tap the motor with a punch. The repeated pounding will take a toll on the bearings. Or maybe set the motor shaft on a punch and hammer off the fan.

Sixto
95 S420
91 300SE
87 300SDL
83 300SD

#4 08-08-2003, 03:13 PM

What's involved in getting the motor assembly out of the car? If it is indeed the brushes I may visit a starter/alternator rebuilder. I suspect that they would have a good assortment of brushes to offer. They only charged me $15 a few months ago for the front and rear bearings to go in my alternator so I suspect they would be reasonable on the price.

jfikentscher · #5 08-08-2003, 03:13 PM

Same thing on my car. If you do a search on blower motor you will find my post. Basically you need to find a brush that is high in carbon or you will ruin the commutator (SP?). I was given a pair of brushes from the local small electric motor repair shop. Still working fine!

Good luck,

Joe.