The heater blower does not work at all, even in the high switch position. But in the high position, and only in that position, there is a constant humming sound from the heater relay. I have tested the blower motor which is ok, and a repacement heater relay did not change the situation. The blower resistor is probably defective, as the blower only worked in the high posistion for some time, but now there seems to be an additional problem.
Its cold in Norway. Any suggestions ??