Fans running all the time?
 

A friend and I have been trying to figure out why his a/c condensor fans are always on. Problem seemed to begin about the time he replaced his a/c compressor. Any ideas/suggestions would be appreciated. The car is an 1995 e300 Diesel. Fans run when a/c is off or on.

Thanks.

High or low speed? Low is controlled by the A/C pressure switch, high by the coolant temp switch on top of the head.

I don't own the car anymore, but I had the same problem. Turned out to be the infamous engine wiring harness problem. The wires leading to the temperature sensor (Front and Top of engine) disintegrated and were shorting out about 12" from the sensor..

I run a new pair of wires from the temperate sensor to their junction box on the Left fender wheel well. It fixed it.

NOTE: Could also be a stuck Relay, but my bet is on the wiring harness.

Phil