Would a faulty indoor or outside air tempaerature sensor cause the Climate Control to not function at all? The Climate Control works when the Temperature Rheostat is turned to minimum. When it is turned up higher, the Climate Control loses its functioning capabilities.

Kevin E. Ryan

Two common problems seen here. Loss of vacuum under the hood, or the potentiometer for the blend air flap is faulty or out of calibration. In any case a tech should take care of this.

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Benzmac:
Donnie Drummonds
1992 500E (very soon I hope
1981 280GE SWB
ASE CERTIFIED MASTER AUTO TECHNICIAN
SERVICE MANAGER FOR 14 BAY FACILITY
MERCEDES SPECIALIST 8 YRS
PARTNER IN MERCEDESSHOP.COM

I should clarify my earlier message. The Climate Control power shuts off entirely. It will work with ignition on for a period of time which varies, but not in engine running mode. The fan shuts off and the air flow defauls to defrost. This varies according to the position of the dial as well. It works with less frequency as the dial is turned to a higher heat setting. This may all be related to your earlier reply, but I would like to be sure before I take it to a MB garage as it is 2.5 hours away. Thank you.

Kevin E. Ryan

The problem on my climate control was solved by disconnecting the auxilary water pump. It is drawing to much current and thus shutting down the entire system. Strange, but true.

Kevin E. Ryan

Hi Kevin,
I had the exact thing happen to me, again just pull the electric plug fro the Aux Water pumb located under the hood, passenger side just behind the headlight ahead of the passenger side front tire. Do not pull the water hose, just pull off the electrical plug. Then the regular blower will work and you will still have full functioning of the ACC. The service department did not want to believe this was the problem till I showed them that the system would return to normal operation when the the aux. water pump was disconnected... made a beleiver out of them. I understand you will want to leave this unplugged until you have the pump replaced as if you leave it plugged together for a long period of time the overcurrent situtation (which is what is causing the shutdown in the first place) can in fact damage the ACC system circuit board. Once the aux. water pump is disconnected you can still use the car, you will still have heat all defrost / heat funcitons... it may just take a short time longer for "hot" heat. Hope this helps.

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Jo

Dear Starfish,

Thanks for your post. Disconnecting the power from the auxilary H2O pump is exactly what I did. An old Mercedes mechanic from Maplewood Motors in St. Paul, MN told me about this one. I gave him a tip on fixing a fast idle on a 190E-2.3 that he had not heard of in return.

Sincerely,
Kevin E. Ryan