heater control help!!!!

[632bbc]

Anybody have an idea what would cause my fan to only work on high? I turn it to the lower settings (1-3) and it doesn't work but as soon as you put it on 4 it blows good. . .

[bwood]

Sounds like a bad blower motor resistor. The blower motor resistor uses multple resistors inside to vary the amount of voltage the blower motor gets. In the low speed, it cuts the volatage the most and also generates a high amount of heat, in med, it cuts the voltage a little less and in high, the resistor is basically bypassed and the motor gets whatever the system/battery voltage is. The resistor is usually mounted near the fan in the fan housing. It is usually held in with two screws and has 4 or more wires on it, depending on the amount of speeds. It is in the housing as it uses air from the fan to keep it from overheating.