Aux Fans in C220 not working
 

I have a '95 C220 with 115,000 miles. The aux fans never come on. When stuck in traffic the AC is not effective and if the outside temperature is over 95*F, I have to turn on the heater to keep the temperature at 90*C to 100*C. When the outside temperature is 90*F or cooler the AC works very well and the engine temperature fluctuates between 80*C and 90*C. I could not find the fuses for the aux fans.
Any input appreciated.

Danny
'95 C220

Is the fan turning at all? The fan should kick onto high speed at coolant temp of 106C. It will turn at low speed pretty much the rest of the time. Might be the electric fan motor or a relay.

Check under the panel behind the fuse box.
Low a/c fan relay is suspect of having a blown fuse on top of relay...

The aux fans on our C220 seem to be activated by both AC use and engine temperature. At lower engine temps, they cycle on and off frequently with the AC on, but not with it off. At higher temps, they come on when the guage is just under the 100 mark, run for a while and shut off.

Howdy.

I've got the exact same issue and symptoms on my 1997 C230 with ~95k miles The service appointment is scheduled for next week. I would be forever grateful if someone figured out that the problem is some little thing like a blown relay. For no particular reason I suspect that's not the case, but...

A few weeks ago, I found the relay area in question behind the main fuse box but was confused about which one it was. As far as I could tell, the "fuse map card" did not correspond to what was actually in there. I think I finally figured it out by process of elimination. I went to the dealer's parts department and asked for a new one. The one I took in was green (getting a little hazy now) and they sent me home with a light blue (or vise versa) one with the same part number on it. The little prongs on the blue one did not match the green one. I plugged it in just to see what would happen. As it did not solve the problem, I took it back.

I'm not sure why, but this really bugs me. I should have taken it for service weeks ago, but I've been stubborn and wanted to figure it out myself. It's really not a cost issue. It's having to admit that something broke just after the 90k service and I have to go back before I had planned to.

If you figure out what's wrong and let me know, I'd really appreciate it.

Fixed Aux fan problem
 

I appreciate all of the replies. I took the car to my mechanic today. Turns out the high quality insulation around the wires leading to the fans had disintegrated damaging the wires. Also, the temperature sensor was defective.

Dan