How does a blower motor resistor control speed?
Many blower resistors control current to the blower motor in all speeds except high. In high speed the resistor is bypassed and power is fed to the motor directly from the switch. Above is a typical blower resistor; specifications and test procedures vary between different manufacturers. Place one lead of the Ohmmeter on terminal 1 of the resistor.
What are the symptoms of a bad heater motor resistor?
Symptoms of a Bad or Failing Heater Blower Motor Resistor. 1 1. Blower motor stuck on one speed. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. The blower 2 2. Blower motor does not work on certain settings. 3 3. No air from the vehicle’s vents.
What does the resistor on a heater do?
It is responsible for controlling the blower motor’s fan speed. 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.
How much does it cost to replace a blower motor resistor?
The blower motor resistor or control module replacement is not very expensive. For example, one of our colleagues had a problem with his 2011 Ford Escape: the fan only worked at the speed 4. He paid $50 to diagnose and $112 to replace the resistor at a local Ford dealership.
How does a blower motor resistor control the fan speed?
The blower motor resistor controls the fan speed of the blower motor and the resulting change in air pressure produced by the movement of the blower fan. It accomplishes this by regulating the electric current that powers the motor.
What are the symptoms of a failed blower motor resistor?
Blower motor resistor problems. Problems with a blower motor resistor are common in many cars. The most common symptom of a failed blower motor resistor is when the heater fan only runs at high speed and doesn’t work at low speeds.
How is the resistance measured on a heater blower?
If the appearance is normal, it is necessary to a degree the resistance throughout every individual resistor. The resistors are all linked to a single common point. Switch the multimeter to the resistance measuring mode, connect one probe of the multimeter to the commonplace point and use the other probe to degree resistances at other points.
How much does a blower motor resistor cost?
Depending on the manufacturer and model, a blower motor resistor can go anywhere between $3 and $335 on CarParts.com. The replacement parts come in individual units, sets of two resistors, or as part of a blower motor resistor kit.