At what temperature are the auxilliary fans supposed to come on in a '95 C280? Mine never seem to come on, even at temperatures close to 110. The do come on when the A/C is on, but only for very short durations. I don't have access to wiring diagrams or any other shop information and would like to know where I could tap in a parallel circuit to run the fans manually when desired. Also, what controls the fan relay, is it the temperature sending unit or something else. Thank you.

There are 2 speeds & 2 relays that control the fans, from the sound of it one of the fan relays have a blown fuse. The relays are under the rear section of the fuse box (under hood). Look for BLUE relay.

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MERCEDES BENZ MASTER GUILD TECHNICIAN
ASE MASTER TECHNICIAN
27 YEARS DEALER M.B. Shopforeman
190E 2.3 ITS RACECAR
1986 190E 16V