I DO BELEIEVE THERE ARE TWO SEPARATE CIRCUITS FOR AUX FAN ACTIVATION. (TWO SEPARATE VOLTAGE SOURCES). THE REMOVAL OF THE SENDING UNIT CONNECTOR ACTIVATES HIGH SPEED FAN AS A DEFAULT.THIS IS THE SAME AS OTHER MID 90'S MB'S(i.e C280)....ONCE AGAIN, ID RECOMMEND CHECKING THE FUSED RELAYS IN THE BACK OF THE FUSE BOX.
