Possible Causes
REAR BOOSTER FAN REAR CONTROL SWITCH
REAR FAN ON INDICATOR DRIVER CIRCUIT SHORTED TO GROUND
REAR FAN ON INDICATOR DRIVER CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)
REAR BOOSTER FAN REAR CONTROL SWITCH
REAR FAN ON INDICATOR DRIVER CIRCUIT SHORTED TO GROUND
REAR FAN ON INDICATOR DRIVER CIRCUIT OPEN
AUTOMATIC TEMPERATURE CONTROL (ATC)