Intermittent HVAC blower
08-21-2012, 11:03 PM
#1
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1984 300D
Intermittent HVAC blower
Hi, all;
When I first got my '84 300D (spring 2011), the blower motor would operate intermittently and blow the fuse. I replaced fuses and cleaned contacts on the climate control unit (the thing with the pushbuttons) and it worked better, but still intermittently, with defrost working most of the time and the others sometimes. Sometimes the fan would come on while I was driving, but wouldn't come back on after turning off the engine. Now (summer 2012), I get nothing. When the fan was working, the only problem was a slight squeaking (very slight), so I don't think it's the blower motor (yet).
I also don't think it's the dash sensor.
I can hear a flap or gate open after I start the car.
The a/c compressor froze a few months ago (I just want some air movement for now, a/c repairs later).
From what I understand, there are three possibilities: the aforementioned climate control unit, the blower motor resistor, or the blower control switch. Before I blow (no pun intended) about $500 on all three; I'd like to know which is most likely to be the problem, and if there is a way to test.
Thanks (sorry if I got all TMI here; I don't know what may or may not be relevant).
When I first got my '84 300D (spring 2011), the blower motor would operate intermittently and blow the fuse. I replaced fuses and cleaned contacts on the climate control unit (the thing with the pushbuttons) and it worked better, but still intermittently, with defrost working most of the time and the others sometimes. Sometimes the fan would come on while I was driving, but wouldn't come back on after turning off the engine. Now (summer 2012), I get nothing. When the fan was working, the only problem was a slight squeaking (very slight), so I don't think it's the blower motor (yet).
I also don't think it's the dash sensor.
I can hear a flap or gate open after I start the car.
The a/c compressor froze a few months ago (I just want some air movement for now, a/c repairs later).
From what I understand, there are three possibilities: the aforementioned climate control unit, the blower motor resistor, or the blower control switch. Before I blow (no pun intended) about $500 on all three; I'd like to know which is most likely to be the problem, and if there is a way to test.
Thanks (sorry if I got all TMI here; I don't know what may or may not be relevant).
08-28-2012, 03:21 PM
#2
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Answer
It sounds like the blower motor brushes are worn down.
You can remove the old motor brushes.
Take them to a hardware store, electric motor repair, starter - alternator shop.
There are also several ebay vendors selling the brushes.
Install the new brushes, and the motor should last another ten years.
roy@pelicanparts.com
.
You can remove the old motor brushes.
Take them to a hardware store, electric motor repair, starter - alternator shop.
There are also several ebay vendors selling the brushes.
Install the new brushes, and the motor should last another ten years.
roy@pelicanparts.com
.
