help heater blower not workin 94 s420
01-09-2007, 06:36 PM
#2
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92 500sel/01 320e wag
The blower motor is not fused, it is controlled by the speed regulator (electronic) mounted on the blower housing. The regulator is in the ground side not the hot side. I suspect the regulator, the blower motor shaft also rusts onto its bearing, and the electronics from the heater, in that order.
The blower motor sits below the drivers side windshield, It is covered by an oblong cover that has red and blue hoses going to it. There are six large phillips screws, disconnect the hoses and sensors, lift up the cover, and you should see the triangular filter, under the filter is the blower and regulator. if the blower spins it is not seized, the next thing would be the regulator. The bearing usually makes some noise before it seizes, try putting some ATF on the shaft to lube it if that is the case.
see this article
http://www.mercedesshop.com/Wikka/W140BlowerMotor
The blower motor sits below the drivers side windshield, It is covered by an oblong cover that has red and blue hoses going to it. There are six large phillips screws, disconnect the hoses and sensors, lift up the cover, and you should see the triangular filter, under the filter is the blower and regulator. if the blower spins it is not seized, the next thing would be the regulator. The bearing usually makes some noise before it seizes, try putting some ATF on the shaft to lube it if that is the case.
see this article
http://www.mercedesshop.com/Wikka/W140BlowerMotor
Last edited by Peter Guenther; 01-09-2007 at 06:39 PM.
03-12-2010, 05:53 PM
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W140
I have changed 3 regulators in less than a year.
Now when I hit a bump or make a hard turn the fan shuts down.
Any ideas would be appreciated. Could it be the blower motor?
R49
Now when I hit a bump or make a hard turn the fan shuts down.
Any ideas would be appreciated. Could it be the blower motor?
R49
03-13-2010, 12:10 AM
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1996 S320 SWB, 1998 S600
I would recommend cleaning and lubing the blower motor. 20w non-detergent motor oil is also good for most small sleeve bearing motors. You could have a loose electrical connection as well. Possibly at the solderless connectors on the motor. The excessive current draw could be wearing the regulators out.
03-15-2010, 07:22 AM
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I will do that. The other thing is the blower motor at times has a low humming sound. Was thinking of replacing the motor with a new one or buying a new assembly but they are 700.00
03-15-2010, 09:24 PM
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1998 and 2002 SL 500, 2014 E550 Convertible
I have the exact problem...humming...more pronunced at higher fan speeds....motor needs to be replaced.....ebay has many....inexpensive without the resister.....I tried the 20w oil....lasted a few days and the sound came back....junk yards have them and the post abouve yours...he's parting out his S500...buy his motor!
03-15-2010, 10:29 PM
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1996 S320 SWB, 1998 S600
I was lucky my problem was in the climate control unit, and I cleaned & lubed at that time. When a motor becomes noisey, the damage is done.
Buy the assembly, the OEM blower wheel is press fit plastic onto the shaft. I'm not sure how the replacement is set up. They run in the $200.00 range
Buy the assembly, the OEM blower wheel is press fit plastic onto the shaft. I'm not sure how the replacement is set up. They run in the $200.00 range
Last edited by napaAl; 03-15-2010 at 10:34 PM. Reason: additional info
