M30, E34 Auxillary Fan

[LeaTHER OpT. 28]

Over this past weekend I had Big problem with my fuses. Heater fuse blew while i was driving and it melted part of the fuse box. As i was looking it over i noticed that there was a 25 Amper fuse in slot #25, where there needed to be a size 30 Amper. The fuse was obviously blown, and the manual says the fuse is for the "Auxillary Fan". Does anyone know what this Auxillary fan is for??? Since the fuse was in there when I bought the car, I don't know what to look for that is now working. Any Ideas?

[ShadeTreeBill]

It's in front of the radiator and provides "auxiliary" cooling to the radiator when the AC is on, and also if the car starts to run hot for other reasons, like just very hot weather.

The most common symptom of a problem with the aux fan is that the car cools fine when driving, but slowly starts to overheat when idling in traffic for a while. Usually in summer when running AC. I had this problem last year, and found the Aux fan resisitor was open and needed to be replaced.

There is a switch (temp sw) on the right side of the radiator that controls the fan, it's behind a plastic cover. I think there are actually two fuses for the fan, one for high speed, and one for low speed. I think the fan runs constantly on low speed anytime the AC is on, and the car is at operating temp.

Hope this helps! Good luck!