aux fan ?
 

WHILE DRIVING NOTICE TEMP RISING TO NEAR 120 MARK. I HAVE A 94 E420 BOTH FANS COME ON WHEN TEMP GET UP THERE . IAM LOST WHEN SOMEONE SAY LOW/HIGH FANS DOES THAT MEAN WHEN AC IS TURNED ON THE FAN ON DRIVER SIDE SHOULD COME ON I READ OTHER THREADS AND CHECK THE BLUE/GREEN FUSES THEY ARE GOOD I DID THE WIRE TEST WHERE U TOUCH THE WIRES WITH SCREWDRIVER BUT IT DOES NOT COME ON BUT WILL COME ON WHEN TEMP GOES NEAR 120. I TEST THE ANTIFREEZE FOR THE 50/50 IT WASNT. GOT IT CLOSE TO 50/50 NOW. TEMP STILL RISES COULD I GET SOME FEED BACK ON IT. ONE OTHER THING ALSO IS MY TURN SIGNAL AN MY WASHER INTERMIT WILL WORK FOR A SECOND THEN STOP I CAN HIT A BIG BUMP IN THE ROAD IT WILL START FOR SECOND AN STOP AGAIN COULD THIS BE A SHORT AN NO HAZARD LIGHT:confused:

Your problem could be caused from a bad temperature sensor that screws into the head or the wire connection could be bad. Its a blue and screws in the head. This will cause your fans not too come on since the engine is getting misinformation about the temperature.