Bad Switch/Blower Motor Resistor Assembly May Cause Inoperative Heater Blower Motor on Mercedes-Benz 420SEL

Other than a defective motor, a bad switch or blower motor resistor assembly can cause an inoperative heater blower motor.

RepairPal Verified
Average mileage: 179,100 (145,000–230,000)
2 model years affected: 1990, 1991
7 people reported this problem
Viewing
1
-
3
of
3
problem details
1990 Mercedes-Benz 420SEL 155,000 mi,
when I place in key and start to turn car on blower will come on sometime when I start the car blower goes off most of the time the blower does not come on at all.
the blower motor was rewplaced 2 years ago and it quit working but i hear noise when i push buttons on air condition compressor is fine no air comes out of the vents
1991 Mercedes-Benz 420SEL 175,500 mi,
you can hear it turn on but no heat or a/c come out of my vents