How do you know if a fan resistor is bad?

How do you know if a fan resistor is bad?

Symptoms of a Bad or Failing Heater Blower Motor Resistor

  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.
  2. Blower motor does not work on certain settings.
  3. No air from the vehicle’s vents.

What causes fan resistor failure?

In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor.

What does a blower fan resistor do?

The blower motor resistor is responsible for controlling the blower motor speed. In the past, this was done by varying the voltage supplied to the blower motor. In newer applications, the blower motor resistor is actually a solid state module that sends a varied signal to the blower motor.

Should I replace blower motor and resistor?

We do suggest that you replace the resistor at the same time. It may not be critical, but this will keep the system more uniform. The issue may even be related to the resistor. If you know that it is not related to the issue, then you do not have to replace it.

How much does a blower resistor cost?

The average cost to replace the blower motor resistor at a repair shop is between $44 and $55 in parts and $70 in labor costs, for a total cost of around $114 to $125.

How do you test a fan resistor?

Place one lead of the Ohmmeter on terminal 1 of the resistor. Place the other lead on terminal 2 and check against specifications. If this circuit is open, showing infinity on the Ohmmeter, the blower resistor must be replaced. Move the lead from terminal 2 to terminal 3 and check this reading against specifications.

How do I know if I have blower motor or resistor?

Symptoms of a bad heater blower motor resistor

  1. Fan does not work at all, so no air comes out of the vents.
  2. Fan only works on some speeds and not others.
  3. Fan only works on the highest speed.
  4. Fan runs all the time and can’t be controlled with the fan switch.
  5. You see smoke coming out of the vents.

How do you tell if it’s the blower motor or the resistor?

If the airflow from the vents is weak… If you try to increase the air pressure and you feel no difference in the pressure blowing, then your blower motor resistor may be failing. A damaged blower motor resistor will work on one fan speed which may not be enough to keep the inside of your car cool or warm enough.

How much is a resistor?

A blower motor resistor costs anywhere between $1 and $400.

How much does it cost to replace a blower motor?

Replacing a blower motor costs $450 on average with a typical range of $250 to $800. With a warranty, you might pay as little as $150 for labor alone. For high-end models, like those with large motors or access issues, you might pay as much as $2,000.