1982 300SD blower problems
 

Ok, so I have no blower. I've burnt out 3 climate control units before someone told me if the aux water pump is siezed it will blow the control unit. SO....I've replaced the aux water pump, the blower and the blower relay with new parts. Today I installed a supposedly good used control unit. No blower.....needless to say, I'm getting frustrated. I didn't see any fuses burnt. Is there a relay involved in all this? If so, is there a way to test it? Any suggestions? The only other thing I can think of is that the resistor pack is bad. How do you test that? How would you test the control unit? I'd really appreciate any help with this, I'm very cold in the car!

RE: 1982 300SD blower problems
 

how's your vacuum system?

My 1984 300 DT does this wierd thing where the ignition switch doesn't always return all the way to "run" after starting, and the entire heating/air conditioning system doesn't work at all unless I bump the key back a bit.
I have had some pretty terrible experiences with heater/air conditioning systems over the years, especially with my 70's cars, good luck
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RE: 1982 300SD blower problems
 

When you mention the Aux pump, I assume you mean the small motor on the servo. The first thing I did was unplug this. You don't need this pump to get heat. (Mine has been unplugged for years, I don't get the same amount of heat but My fuses stopped burning up.).

Secondthing to do is YES, replace ALL fuses in the car. Sometimes the fuses corrode where they don't burn up but they restrict the current neccessary to run the motors in the car. (I've had this problem for both my windows working as well as the heat blower). This in turns blows the push button unit.

Third, check the relays. They are small (apr. 1.4" rectangular shape), that look like big fuses. To ascces them, you take off the bottom panel under the steering column first, then the side panel (yes, behind the hood latch on the left sitting in the car). There are several relays, see if any look burnt. you can swap them around to test them. If it's this buy on ebay.

Let me know how it goes.

Mercedes Scott


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