I think I found the answer: previous post from MrBOCA


Also I do not understand how it turns off with the ignition OFF and door opened. There is no relationship. The regulator is between the battery and the blower motor. The only control is from the climate control. So if the climate control blower control is not adjusting the speed, the regulator is either misconnected or the driver transistor is permanently turned on (burnt). In the latter case, the blower motor will not turn off as long as the battery is connected to the car. You need to remove the power connection to the blower regulator to prevent battery drain.

If the blower regulator is burnt out, ask them to send you a replacement.

Will try this route first

 

Your blower regulator is shorted, possibly due to improper installation.

 

I just rechecked the install, there is a 3 pin connector only fits one way and a single slip on connector, so I think install is ok. part maybe be bad.

 

I did not mean the electrical installation. Do you have the old style blower regulator that is mounted to the blower motor metal frame surface ? Or do you have the new style (with the heatsink that looks like a porcupine) ?

 

Porcuipine

 

Inthat case, you have a bad regulator. The old style ones need to be installed on the metal blower frame with a heatsink paste, and proper torque. Yours has its own heatsink.

Just to be clear this is the porcupine style.

New Blower Motor Resistor Regulator fits Mercedes W210 E300D E320 E420 E430 E55 | eBay

This is the old style:

Blower Motor Resistor Regulator for W210 E-Class Mercedes Benz E320 E420 E430 | eBay

 

the newer style is what is in the car and supplier has already agreed to replace, once MrBoca, thank you. Will let the thread know how this works out as soon as new part arrives, until then when I shut the car down I will unplug the blower.

 

Great

Keep cool

 

The problem with these older style blower resisters is it has power to it all the time. I have replaced mine 3 times in the last ten years. I did install a shut off switch to the neg. battery side coming out just under the rear bumper right side.

 

Please update your profile with your model and model year for your car, so people will know what type of system you have.

The newer ones have integrated heat shields on them, and also protective circuits (if from a reputable manufacturer).

Putting a cut-off switch is a bit overkill, if it is for this problem. You could just unplug the blower / regulator plug.