Blower motor brush replacement help - PeachParts Mercedes-Benz Forum

ericzacha · #1 08-17-2006, 12:24 PM

I'm trying to refurbish the blower motor in a w126 1988 300 sel. It has been slowly getting louder over the past few months and has taken 10 minutes of driving on a coupe occasions to get started.

I have got the blower out, but I have some questions about replacing the brushes. In the picture below, you can see that I have the brushes out of the housings. My question is, can I just cut the braided copper wire leading to the old brush and just solder the new brush wire to the old, or do I have to disconnect the old wire completely from the base and attach the new wire there? Also, I keep reading about people lubricating their motors to keep them quiet, but I'm not sure exactly where to lube. Do I just put a couple drops of ATF on the new brushes and call it good? Sorry if these questions are elementary; I love to tinker, but I have very little electronics experience.

dmorrison · #2 08-17-2006, 12:35 PM

Yes you can just cut the braided wire. but look at the bend in the wire when installed. Remember when you solder the new wire that joint will be stiff and not very bendable. So locate the solder joint at an appropriate position.

Oiling the motor means oiling the bearings, not the brushes. The bearings are located at the top and the bottom of the armature. Look at the shaft and you will see them.

Dave

ericzacha · #3 08-17-2006, 02:29 PM

Thanks Dave, that't just what I needed. I plan on posting my pictures and a "how to for dummies" soon.

buellwinkle · #4 10-02-2006, 06:56 PM

Quote:

Originally Posted by ericzacha

Thanks Dave, that't just what I needed. I plan on posting my pictures and a "how to for dummies" soon.

Did you get a chance for that "dummies" book yet. I needed to change the brushes on the blower in our SLK230 but where can you get brushes that fit and work in there?

ericzacha · #5 10-03-2006, 08:18 PM

You know, my wife went and took our digital camera with her to her sister's house when I finally had time to fix the blower. I ended up buying the brushes for about $6/pr from carbonbrush.com vs. something like $20 from Mercedesshource or George Murphy at Performance Analysis. If you buy from George Murphy he does send you an instruction booklet that walks you through it. Might be worth the extra 14 bucks. I am not super familiar with the SLK 230 so I don't know how to get to the blower. Once you get that out, I imagine it would be about the same. Feel free to ask for help once you get the blower out. You can PM or email me if you like.

ramjensen · #6 10-03-2006, 10:20 PM

Eric, I plan on lubing my blower soon, and since it's a pain to get to, I will probably replace the brushes while I'm at it. I'm told sewing machine oil is the way to go. As for the brushes from carbonbrush.com, do you have a p/n you used to order them or did you order them by size measurements? Please give me info so I can order some for myself and have them before I pull everything apart. Thanks in advance.

ericzacha · #7 10-04-2006, 06:25 PM

See this link: Rebuilt my 300TD fan motor today

Maki has already done most of the legwork. The people at carbonbrush.com seemed to know which part I needed by my car and motor type, you might try giving them a call.

ramjensen · #8 10-06-2006, 10:37 PM

I just took my blower out. Carbonbrush.com wants dimensions of the brushes, they can't tell you what your car needs by model or anything. So I took the blower out to check it out. It turns stiff. My only symptom when using the ACC is that the blower constantly chirps. I thought lubing it might fix that. One question, though. How freely should the motor turn? I can spin it more easily now that I lubed it with some penetrating oil, but it doesn't freewheel for more than a half turn or so no matter how hard I turn it by hand. Anybody know if it should freewheel? My brushes look to be at least half there still so I'll probably leave them.

Matt L · #9 10-06-2006, 10:59 PM

If the blower's out, I assume that the electrical connections are open. In this case, it should turn very freely, and should indeed freewheel if you spin it.

Your bearings are bad. If you can't replace them, it's time for a new blower motor. Oiling them may help for a while, but the problem will return.

ramjensen · #10 10-06-2006, 11:28 PM

What am I looking at when I look into the holes in the back of the plastic box which I took my blower motor out of and I see fins. Looks like maybe my AC evaporator? Or is it my heater core? Either way it is partially plugged up with black soot-like stuff. How do I clean this stuff out? If I spray this area with brake cleaner, will it drip inside my car? Does the bottom half of the plastic box which houses the blower and also obscures part of this clogged up fin thing need to be taken out in order for me to adequately clean the fins? If so, how?

ramjensen · #11 10-09-2006, 09:07 AM

OK, I did my homework and now realize that the fins clogged with soot/dust/whatever behind where I took out my blower motor are the fins of my evaporator. I have found some evaporator cleaners online for $15-20 plus shipping. Can I just clean it with brake cleaner?

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