Questions and Answers

Mercedes Benz 190E Cooling Fan Q. Hello there, I have a 1984 Mercedes Benz 190E 2.3 liter engine. I have a big problems with my cooling fans. Inspite fuses are okay both the A/C fan and the radiator fan will not come on. I know that the clutch for the radiator fan is working. What to do? The car gets hot and no fans spinning, just the clutch coming on. Please give an advise. Regards, Erik

A. I would double check all the fuses. Those funky ceramic fuses are known for biting mechanics in the ass. They may look and test good, but the contacts get corroded and will not make good contact. A little sand paper to clean the contacts on the fuse and in the fuse box will insure a good connection.

Then run a wire from the battery positive to the red wire in the fan motor connector and a wire from the battery negative to the black wire. If the fan runs, then you know the fan motor is good. Now remover the jumper from the black wire. If the motor stops, you have a bad ground.

Then unplug and check the 100° C switch with an ohmmeter. It should be open below 100° C and closed above 100° C. Grounding the brown/blue wire for the 00° C switch should make the fan come on.

If not, then the problem is with the Auxiliary Cooling Fan Relay, the Auxiliary Cooling Fan Pre-resistor or the wiring connecting them.

The Auxiliary Cooling Fan Relay is on the left side of the component compartment, in the auxiliary relay box.