Originally Posted by 04crossfi-er

radiator light is not on. temp gauge is good. temp has always been good prior to this. only over heated one time sitting in bumper to bumper traffic. good fan would have turned on at that point prior to this im guessing.

i found a post on here that you replied on back in 08/2011. mechanic had same issue with a clients crossfire. based on that, the two differing part numbers, chrysler and mercedes, were deemed to be the same in that post.

found in that post that another mechanic installed a new radiator fan in the car and wired it improperly causing it to have fan stuck on high. mechanic asking the question on forum was then able to correct wiring and fix car.

fcm in my car is very clean, no engine dirt, im going to guess it was replaced by dealer.

everything else is fine in car. i looked at the wiring and all connections were good.

there is a mercedes specialist in town. probably going to take car there for second opinion