Heater Blower Motor Fan Resistor

Heater blower motor resistor symptoms no air blowing through vehicle s vents.

Heater blower motor fan resistor.

Problems with a blower motor resistor are common in many cars. In some cars a failed blower motor resistor can cause a heater fan to. The blower resistor is connected in series with the blower fan. Since the blower resistor is directly responsible for transferring power from the battery to the blower itself a symptom of.

The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. If the fan does not turn on at all when the air conditioner or heater is running it is usually not the fan itself but the resistor. The fan switch may be at fault but a more likely reason is that a blower motor resistor that controls the voltage going to the blower has packed it in resulting in only one speed remaining. Blower motor resistor control module problems.

When fan speed is changed via the knob on the instrument cluster the blower motor resistor changes setting which changes the speed of the blower motor. This means that the current running through the blower motor and thus is speed is controlled by the resistor value. The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting 4 or 5 and doesn t work at low speeds.