HEATER FAN QUIT WORKING ON 1 2 AND 3. BUT SOMETIMES WOULD COME BACK ON, WHEN ON 1 2 OR 3. AND WHEN IT WAS ON YOU COULD SMELL PLASTIC BURNING. AND WHEN CHECKED THE INTO IT FOUND THE PLUG ON THE WIRING HARNESS THAT PLUGGED INTO THE RESISTER ON THE FAN WAS LOOSE AND CAUSING THE WIRES TO MELT. THIS LOOSE PLUG WAS LOOSE FROM THE FACTORY, NO WAY COULD HAVE GOT TOO SMALL OVER THE YEARS. NEW PLUG AND NEW RESISTER PLACED CONCERN IF FIRE RESULTS COULD CAUSE DEATH INJURIES, GARAGE FIRE OR HOUSE FIRE IF VEHICLE PLACED IN GARAGE AT NIGHT. *TR