Hello all,

I've been having an ongoing issue with the blower motor on my 1983 300SD. First off, the car has 127k original miles, and I have the full service history. I can see that a few years back the original owner had the Climate Control pushbutton unit replaced.

Now, on to the issue. I typically leave the push button unit on "EC" at all times. When I start the car the first time in the day the blower motor starts like normal and works through all functions, the A/C blows ice cold. The blower then runs for a random amount of time before turning off. Cycling through the push buttons does nothing. I can, however, feel a difference in engine power when I push the "normal" function which would turn the A/C compressor on. But no blower motor.

If the car sits for awhile the blower motor will come on when the car is restarted. It also comes on every time when started for the first time during the day. Sometimes it runs for 5 minutes, sometimes 30 minutes. I have tried wiggling the ignition tumbler, it does not seem to have any effect....

Thank you in advance for any assistance you can offer!