Auxiliary Fan Stays On
 

have just purchased a 1979 240D. After driving it for a bit yesterday, the auxiliary fan would not turn off - I ended up having to disconnect the power cord.

The temp guage never registered above 175, so, from what I understand, the fan should not have turned on in the first place.

So...

1. Is it possible the Aux fan switch is the problem - if so where is it located ?

2. Is there a temperature detection switch that could be stuck on - again where is it located ?

3. Is there a relay that could be the cause - again where is it ?

Any and all advice is welcomed.

Jeff