Why Does My Heater Only Work On High?

by | Last updated on January 24, 2024

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Most car manufacturers use a series of resistors to make the blower motor run at different speeds. And when one or more of these resistors burn out , you're usually left with only one heater blower motor speed—high. ... Remove the screws, and swap out the resistor module.

How much does it cost to replace a blower motor resistor?

The average cost for a Blower Motor Resistor Replacement is between $108 and $137 but can vary from car to car.

How do I know if my blower motor resistor is bad?

  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.

Can you repair blower motor resistor?

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. On the other hand, you can easily fix the blower motor resistor at home in about an hour (even if you're a beginner) and for around $70.

Does the blower motor resistor control heat?

The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. It is responsible for controlling the blower motor's fan speed . ... A failed blower motor resistor can cause issues with the operation of the entire heating and air conditioning system.

How long does it take to replace a blower motor resistor?

takes about 45 minutes .

What would causes a blower motor resistor to go bad?

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 bad blower motor sound like?

You might hear this as a noise coming from directly behind the vent, perhaps a light slapping , or a sudden pop before you notice a problem with airflow. Whirring noises might also result from a bad bearing in the motor. ... This is a telltale sign of a bad blower motor.

Is there a fuse for the blower motor?

If the fan doesn't work, before pointing the finger at the blower motor, check fuses for the motor to make sure they're still good. Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side.

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.

How do I reset my blower motor?

  1. Step 1: Turn off the power to the furnace. ...
  2. Step 2: Remove the blower compartment cover. ...
  3. Step 3: Make sure the blower is completely cooled off. ...
  4. Step 4: Locate the reset button. ...
  5. Step 5: Press the button in (assuming that this is your issue and that the button has popped).

What happens when blower motor relay goes bad?

If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow . Any sort of electrical spikes or excessive current from a bad relay will blow the fuse and cut power in order to protect the system.

How do you test a blower motor 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.

What does a resistor do on a cooling fan?

The cooling fan resistor is meant to send power to the fans in steps , so that the fans may operate at different speeds. If any of the individual steps or switches fail, it will disable the cooling fans from operating on that speed setting.

How do I know if my climate control module is bad?

  1. Inconsistent cooling. Because the AC control module controls and regulates all of the functions of the system, you may begin to notice cooling inconsistencies when there is a problem. ...
  2. Out-of-date software updates. ...
  3. Uneven air distribution.

What causes heater resistors to burn out?

Trent, one of the biggest reasons for blower motor resistors to have shorten life is actually because of faulty blower motor drawing too many amps , some times melting wires/plugs, heating up resistors shortening their life.

Charlene Dyck
Author
Charlene Dyck
Charlene is a software developer and technology expert with a degree in computer science. She has worked for major tech companies and has a keen understanding of how computers and electronics work. Sarah is also an advocate for digital privacy and security.