Where is the Aux Fan Relay?. s350d, 94
 

Hi
I have my aux fan stuck running after shut the engine off. It will stay running over night and will keep on running until I pull the fuse out. The possibility is the relay that might be stuck closed. I already looked in and under the fuse box in the eng compartment, but can't find any relay.. the car info is 1994 W140 S350 diesel. Can somebody point me to the location of the relays? I have the feeling that it is different from W140 gas model.
Thanks in advance.

Just a guess. On my e300D both fan relays are behind the fuse box. When you remove the cover on the fuse box, there is another cover over the relay box. I had to remove 6 screws to remove the cover.

aux fan relay
 

Thank you, Jay. I already looked into the box last weekend, didn't see any relays at all but found the wire from the aux fan fuse (30 amp) leading through the firewall into the interior. I also looked inside underneath the dash still no relay. This weekend I will look into the 2 resisters in front of the 2 fans to see if they have anything to do with this incident. For now I just pull the fuse out when I park..! I will look more into the CD on different year, might come up with something..!
Thank you.

Same problem, 3 years later...
 

1995 W140 S350

Same thing happened to me Thursday night. I came out from the hotel and it was completely dead. I checked the battery with a Fluke. It read .693 volts. The battery was completely dead.

When we hooked up for a jump start and noticed that the two aux fans came on with the keys in my pocket.

Any idea on where to look?

The choices are:
-Stuck relay
-Stuck temperature switch
-Possibly stuck AC Pressure switch

-Jim