Why Does My Blower Motor Only Work On High?

by | Last updated on January 24, 2024

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Resistor module replacement

Most car manufacturers use a series of resistors to make the heater blower 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. The resistor module is easy and inexpensive to replace.

Why does my air only work on high?

When a blower resistor fails, the highest fan speed usually is the only one that still works because it

essentially bypasses the resistor and receives the maximum amount of voltage

. When the resistor is working, it reduces the amount of voltage going to the lower fan speeds, so the fan runs slower.

Why does my car only blow air on high?

When a

resistor fails

, the fan will often run only at higher speeds or the highest speed, no matter what fan speed is selected. … If little air is coming through the vents (hot or cold), then it could be because the blower motor for the fan or a switch or resistor that controls fan speed isn't working.

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.

Why is my AC in my car barely blowing air?


Your air intake is clogged

, meaning that air isn't getting in from the outside at all or isn't circulating properly. There is a blown fuse in the ventilation system. Electrical issues such as a bad relay. Damaged blower motor.

What are the signs of a bad blower motor resistor?

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

How do I know if I need a blower motor or a resistor?

A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. The blower motor resistor is

the component directly responsible for controlling the blower motor fan speed

. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.

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.

Why does my AC only work when I'm driving fast?

A/C Condenser Fan

The A/C condenser fan's job is

to keep the A/C system cool so that it runs efficiently

. … This will likely cause your air to change temperatures rapidly when your struggling condenser fan is no longer receiving any help from the wind you experience when driving down the highway.

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 long does it take to replace a blower motor resistor?

takes

about 45 minutes

.

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.

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.

Does AutoZone do free AC check?

If you want to find the right AC solution for your car, you can either shop online or go to your local AutoZone.

You can get your car's parts tested for free at AutoZone.

How can I increase the air flow in my car AC?

  1. Start the AC While Driving. A lot of people tend to start their AC before driving. …
  2. Window Shades. …
  3. Inspect the Refrigerant. …
  4. Keep the AC Condenser Clean. …
  5. Inspect the AC Filter. …
  6. Switch the AC to Recirculation Mode. …
  7. Install an AC Curtain. …
  8. Park Smartly.

How much does it cost to fix AC fan in car?

The replacement parts will cost you anywhere from

$200 to $400

. This includes parts and labor. The labor tends to be around the $80-$90 range for replacing the AC fan, but with some vehicles, it can cost you closer to $120. The price of parts varies based on what kind of car you have as well.

David Evans
Author
David Evans
David is a seasoned automotive enthusiast. He is a graduate of Mechanical Engineering and has a passion for all things related to cars and vehicles. With his extensive knowledge of cars and other vehicles, David is an authority in the industry.