Aux Fan 88 420
 

I thought the large electrical fan in front of the radiator should go on immediately when the AC starts.. I was checking the oil today, and had my wife start the car and turn on the AC to see if the fan started.. It didn't.. I don't see any blown fuses, so is it temp controlled ? or another issue ?

If it's anything like my 300 SEL, the fan will start when the A/C high-side pressure is high enough. With mine, the fan usually starts less than a minute after a cold start with the A/C on. The fan will also run if the engine temperature gets high enough.

HTH