124: heater fan poor flow, improves when cornering

[Paul T]

1995 E320 wagon, 188k miles. Heater blower/fan is not blowing much air. BUT, on a hard right turn, the fan speeds up greatly for the duration of the turn. Seems like centifugal force, right turn only, improves fan speed dramatically. Could it be water in an air-box? Bad bearings? Any ideas?
Thanks, Paul T

[d.delano]

Perhaps the motor brushes are worn out? Unless you hear grinding or knocking noise the bearing should still be OK. Brushes are replaceable if you can use a soldering iron. Beats the alternative of buying a new motor.

I took mine out recently and the blower enclosure was full of leaves. This caused a flapping noise. The blower was also working intermittently. Turns out it had whatever they use for insulation under the dash wrapped around both of the motor shafts inboard of the fan cages and it was binding the whole thing up under current. Apparently that stuff gets sucked up into the squirrel cage and winds itself around the shafts. I wouldn't be surprised if that's the cause of a lot of burned out motors. Brushes were fine so I put a drop of trans fluid on the shafts at the bearing and hit the commutator with some contact cleaner. Works like it should now.

Try jiggling the switch as well, it might be worn out. These blower motors will need for you to check on them every ten years or so. It's not difficult but you do have to remove the wiper to get at it.

[Paul T]

Thanks for that, D.
It seems so odd that the fan revs right up the instant i throw the car into a right turn: Revs up instantly with the turn-in, and continues to rev high as long as the centriugal force / turn is happening. Straighten out the wheel and the fan speed drops right off. With the road noise at speed, its difficult to hear, but there is no grinding or squeeling; just a very low motor boat sound.

[d.delano]

yours has a regulator and might have a dust filter as well, may want to check those out

[whunter]

My first suspicion would be the bushings need lubrication, and/or the filter is plugged.

You will need these links.

W124 Blower Motor Removal Photos
W124 Blower Motor Removal Photos - PeachParts Mercedes ShopForum

MONO BLADE VERTICAL parked windshield wiper
windshield wiper

Hesitating Wiper Repair
http://202tech.mkosonen.com/howto/wiper.html




.

[Paul T]

Very helpful. I assume the 1995 blower will be similar to the 1990 coupe.
I don't know what to expect. I have no squeeling, screeching, and the centifugal force of a right turn causes an instant increase in blower speed. I will report back after I have had a chance to go in there.
Thanks again.

[Paul T]

The motor and fans for a 1994 w124 cost $199/ The motor and fans for the 1995 w124 cost $400. MB parts does not sell the motor without the squirrel cage fans. I had the new motor on hand. Here's what I found in the old motor. First, it was the motor, not the regulator or control panel. WHen I first applied 12v to the motor, nothing happened. The good news is that we now knew where the problem was. The brushes were worn down to little nubs and evidently not touching the commutator. But, I pushed the brushes down in thier holder, and the motor spun merrily.
The motor was not built with renewing brushes as a possability. It might be possible to open the brush holder and get at the brushes, and make new brushes, and install them after removing the fans, but the cost to have this done at a motor shop (especially since it appears that the brushes were not designed to be replaced) would be prohibitive.
faced with the prospect of needing the car back together to pick up the kids from school, and the $400 replacement motor, I put the old motor back in place after giving the brushes another push towards the commutator. We shall see if it lasts a month or a year. It worked fine all day today. Thanks for the help.
-Paul T

[emerydc8]

I have a 94 E420 with dust filter. The EPC doesn't depict any brushes--only the motor. Does anyone know if there is a part number for the brushes or a vendor that would know which ones would fit? I have been dealing with the same slowing blower motor in the turn for several years. Thanks.

[d.delano]

Paul, you're supposed to be able to pry the retaining metal that keeps the brushes in place and replace the brushes. You'll need a soldering iron to resolder the new brushes in, push in the backup springs then bend the tabs back over. You should do it before the brushes wear completely and the springs ruin the commutator.

Ace hardware has brushes, just not in the exact same length or cross section. Others have filed them to suit with no problems.

Of course you're not supposed to be able to replace the brushes. The MB paradigm has always been when in doubt buy a completely new unit. MB is hoping you'll give up and capitulate to buying a $300 part. However people have always found a way to fix these unfixable MB components. Just takes a little time and dexterity.

I do it because I enjoy the satisfaction of being a cheap bastard. However recently I had to cough up $300 for a new EGR valve, something one will never feel a benefit from but is essential for passing emissions testing. I tried like hell to find a suitable used part, but in the end had to give up and buy a new one. I have no idea why those things cost so much, they don't look like $300 worth of anything, and the car failed the emissions test anyway.

[emerydc8]

I understand how you feel. Ten years ago I thought I needed a new air pump for my 400E and went to the dealer to buy it. I realized later that I could have simply unplugged the clutch instead of spending over $1,500 for the pump because the pump doesn't even come into play during emission testing and Arizona doesn't verify the status of the check engine light (removed bulb) on non-OBDII vehicles of that year. Any Japanese (Nippon Denso) part connected to a German car is a license for the dealer to steal.

Thanks for the thoughts on the brushes.

[J. M. van Swaay]

In the case of my 94 E320 Wagon (with dust filter) it was possible to buy a Bosch replacement motor without the cages. It does take a little fiddling to remove the cages from the old blower assembly and install them on the new one but it is possible. If I remember correctly the motor was less than $100.

J. M. van Swaay

[whunter]

Originally Posted by Paul T

The motor and fans for a 1994 w124 cost $199/ The motor and fans for the 1995 w124 cost $400. MB parts does not sell the motor without the squirrel cage fans. I had the new motor on hand. Here's what I found in the old motor. First, it was the motor, not the regulator or control panel. WHen I first applied 12v to the motor, nothing happened. The good news is that we now knew where the problem was. The brushes were worn down to little nubs and evidently not touching the commutator. But, I pushed the brushes down in thier holder, and the motor spun merrily.
The motor was not built with renewing brushes as a possability. It might be possible to open the brush holder and get at the brushes, and make new brushes, and install them after removing the fans, but the cost to have this done at a motor shop (especially since it appears that the brushes were not designed to be replaced) would be prohibitive.
faced with the prospect of needing the car back together to pick up the kids from school, and the $400 replacement motor, I put the old motor back in place after giving the brushes another push towards the commutator. We shall see if it lasts a month or a year. It worked fine all day today. Thanks for the help.
-Paul T

Enter these part numbers

MB# 0 130 111 012

MB# 000 830 82 08

into FastLane - Find Your Parts
Enter Part Number.




.

[emerydc8]

Thanks. The EPC shows the part number with filter as A 124 820 06 08, but when I enter that into Fast Lane, the only part that comes up is W0133-1599289 for $328.30.

When I enter the part that the EPC shows without filter, I get a whole selection of motors including a Bosch for $98.28 (#W0133-1609617). Will this fit my car with the filters?

[compress ignite]

Mercedes (Bosch) Blower Brush(s) supplier

SQ Carbon - Mercedes-Benz Blower Motor Repair - Rebuild Kit

[Paul T]

thanks