Mercedes-Benz Forum banner

1990 300e Blower/Fan problem (running only when car is OFF)

1143 Views 5 Replies 4 Participants Last post by  Julian0922
Hi, I did not find an answer after searching for a bit, so I have to open a topic and hope somebody can give me at least a hint:

I own a 1990 300e and the blower fan ONLY works when the car is shut off, as soon as I start the car the fan stops running....

What might be the cause? Battery, the ghost in the machine or...:surrender:? A shortage I would exclude, because otherwise it would do it only sometimes, but it does it EVERY time...and with that I mean hundreds of times. Just that in the autumn and winter a working fan is necessary up here...(WA)

Thanks in advance for the help.... :bowdown:
1 - 1 of 6 Posts
I would look at the ignition wire harness side as the issue. If you pull the tumbler and turn it and the issue isnt there then someone may have changed something as no power should be to it with ignition off. Some people run hot wires and a switch to the motor to bypass the the CCU (climate control unit) and same with the A/C compressor. That way they can have full fan or full AC or both without all the systems safeties shutting it down.

Good Luck.
1 - 1 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.