Plz Help Diagnos AC/Heater Problem
Thread Starter
Newbie
Joined: Oct 2002
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Plz Help Diagnos AC/Heater Problem
Car is a 1990 300e. The blower motor doesn't seem to be working.
- I've tried selecting all of the different buttons on the climate control unit including changing the temperature wheel from cold to hot.
- I've checked all the fuses (in the fuse box in the engine compartment on the driver's side)
- I've removed the blower motor and noticed that the fans were very stiff when turning by hand. I oiled them up and it still doesn't work.
- I checked the voltage on the blue and red wires that go into the blower motor and it read > 12.xx volts. The strange thing is that it read > 12 whether or not I have the ac/heater selected on/off.
Shouldn't it read 0 if I have it off?
If not, does this mean my blower motor is bad?
- I also heard that it could be a bad contact on the climate control wheel. If this is a possibility, how can I remove the wheel to clean the contacts?
And what do I use to clean it with?
Sorry for all the questions, but any advice would be greatly appreciated!
Thanks,
Tygger
- I've tried selecting all of the different buttons on the climate control unit including changing the temperature wheel from cold to hot.
- I've checked all the fuses (in the fuse box in the engine compartment on the driver's side)
- I've removed the blower motor and noticed that the fans were very stiff when turning by hand. I oiled them up and it still doesn't work.
- I checked the voltage on the blue and red wires that go into the blower motor and it read > 12.xx volts. The strange thing is that it read > 12 whether or not I have the ac/heater selected on/off.
Shouldn't it read 0 if I have it off?
If not, does this mean my blower motor is bad?
- I also heard that it could be a bad contact on the climate control wheel. If this is a possibility, how can I remove the wheel to clean the contacts?
And what do I use to clean it with?
Sorry for all the questions, but any advice would be greatly appreciated!
Thanks,
Tygger
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Joined: May 2005
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From: REHOBOTH BEACH DE
88-300CE TWIN TURBO, 99-C43, 05-G55K, 71-280SL, 94-E320 CAB, 08 CLK63 BLACK SERIES
Fan shouldn't be stiff when turning by hand.
The blower cage should turn freely, so possibly a bad bearing in the fan
The blower cage should turn freely, so possibly a bad bearing in the fan
MBWorld Fanatic!
Joined: May 2003
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From: Houston, TX
2015 E250D
your blower fan is seized. It is very common. Replacement is required. Oiling may fix it temperarly but you'll have it do it again very soon. Your blower regulator may have overheated and blown as well. Located on firewall drivers side.
Thread Starter
Newbie
Joined: Oct 2002
Posts: 20
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Ok. if I turn the AC on in the car, should i hear or feel the AC kick on? Right now, when I turn it to cold and the fans on, nothing happens.
Thanks, looks like a new motor is on my shopping list.
Thx everyone
Thanks, looks like a new motor is on my shopping list.
Thx everyone
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Joined: Dec 2006
Posts: 1,042
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From: Bellevue, NE
1995 E320 SE, 162,000 Miles (Sold) 2007 CLK350 Cabriolet 2014 ML550
Depends on outside air temp. If the system is very cold, say less than 35 degrees F it is likely that the low pressure switch will be open and prevent the A/C compressor from turning on. You really need to wait for a mild day in the 50s to be sure if the A/C compressor will run.
