w210 Aux Fans mysteriously turn themselves on
 

Went out to the car at midnight, closed the door then the fans started by themselves mysteriously. Had been sitting for 6 hours so it was cold. Speeds varied as I searched for a fuse. Couldn't locate a fuse for them, so I unplugged the battery. They ran for 20 minutes while searching for fuse and then removing the back seat to access the battery. Anyone had theirs start up on their own before? Should I start with the relay? Thanks.

The aux fans on a 210 are controlled by the "EGS" box which is located in the front left corner of the vehicle.

EPC shows an arrow pointing to the left front corner of the bumper but I suspect it's under the hood behind the left headlight.

There are 2 part numbers based on your VIN. So beware if you hit the yards that you get the correct one.

You can usually turn the aux fans ON/OFF by pressing and holding for 10sec the 2 AUTO buttons on the climate control unit. Also cycle the key a couple of times. There is no fuse for the AUX fans.
http://www.autolib.diakom.ru/CAR/Mercedes-Benz/1997/E300/SYSTEM%20WIRING%20DIAGRAMS/6183.pdf

JayBob..thought the EGS controlled the Transmission located on passenger side ECU area. What would it have to do with the fans coming on?

water?
 

I'm thinking the problem is fixed now. I had hit a major puddle of water as there was lots of flash flooding. I'm thinking the Aux Fan controller was soaked as the water was deep. It is mounted low under the headlight, under the bumper area. Now today with fans plugged in, (the wire plug is in the front grill area under a cap where the High Pressure valve for the AC is located) they are not running on. I'm thinking the connections dried out fixing the problem.
tjts, good to know about switching the fans--I tried it and it worked.

the older model W210 has the fan controller somewhere in the fuse box, the later ones have it under the headlamp area.

In my car the single cooling fan has a 40A fuse