What is a blower motor resistor?

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.

What happens when blower motor resistor goes out?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

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

Signs of a Bad Blower Motor Resistor Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents. Intermittent or inconsistent fan speed.

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

How much does a blower motor resistor cost? To replace the blower motor resistor, it would cost you anywhere between $50 to$150 – this includes the cost of equipment and labor. However, by doing it yourself at home, you can save up to $70.

Will a blower motor work without the resistor?

Without any power, the motor won't run. As a result, the blower fan stays still and silent, and no air blows out of the vents. There are instances where a bad resistor will prevent the current from reaching the blower motor altogether.

What happens when blower motor resistor goes out?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

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

Signs of a Bad Blower Motor Resistor Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents. Intermittent or inconsistent fan speed.

When should I replace my blower motor resistor?

The most common symptom of a bad blower motor resistor is that you will only notice that your blower is working on the highest speed setting or that it won't work at all. The main symptoms of a bad blower motor resistor include: Only One Speed From Blower Motor. Various Airflow Settings Not Working.

Should you replace blower motor and resistor at the same time?

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 do you know if a resistor is bad?

A good resistor should test within its rated range. A bad resistor will either show infinite resistance or a measurement far higher than its rated resistance. In either case the resistor is no longer functioning properly.

What happens when blower motor goes bad?

If the blower motor is completely bad, then you'll have no airflow at all. Strange sounds coming from blower. Blower motors can make all kinds of sounds, depending on what the issue is. Vibrations, grinding, and high pitched-noises are some of the sounds a blower can make if it's going bad.

How long does it take to change a 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 is the difference between blower motor and blower motor resistor?

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.

What causes blower motor failure?

Blower motor breakdown can be the result of anything from old age to failed bearings, high amp draw, electrical failure in the windings, dirt accumulation, and more. “The most common cause is dirt accumulation due to lack of maintenance,” said Tom Beaulieu, president of Bay Area Services Inc.

What causes a blower motor resistor to go out?

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.

How do I 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 happens when a 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.

Can a bad blower motor cause no heat?

Problems with Your Blower Motor or Blower Motor Resistor Without it, there's no circulation of air—hot, cold, or otherwise. The blower motor resistor is the part that controls the fan speed of the blower motor. Both of these components can fail, resulting in the heating system simply not working.

What happens when blower motor resistor goes out?

If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed. The heating and air conditioning systems may still function at one speed, however the resistor will have to be replaced in order for full functionality to be restored.

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

Signs of a Bad Blower Motor Resistor Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents. Intermittent or inconsistent fan speed.

How much should 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 much does it cost to fix a blower motor in a car?

How long do blower motors last in a car?

The blower is supposed to last the entire lifetime of your car. However, situations vary and some climates require the fan to be used too often. Many car owners find themselves having to replace the blower after five years. The quality of the motor used to power the blower matters.

Where is a blower motor located?

The blower motor is usually under the dashboard on the passenger side. Blower motors that make loud squeaks or rattling noises may be worn out and on the verge of packing it in, but sometimes those noises are caused by leaves or other debris that can be cleaned out after the motor is removed from the vehicle.

Is there a fuse for blower motor?

Can a bad blower motor cause overheating?

Recognizing When Your Blower Motor Is Overheating. The blower motor in an HVAC system blows the heated air throughout all of the vents in your house. If this component fails, the furnace will no longer be operable.

What is a blower resistor used for?

A blower resistor uses resistance to control the speed of the blower motor. In high speed, the resistor is bypassed and power is fed to the motor directly from the switch. This illustration shows a typical blower resistor, specifications and test procedures vary between different manufacturers.

Where is the blower motor resistor located?

Blower motor resistor. It's located inside the dash, often on the opposite side of the steering wheel or inside the engine compartment on the firewall. In most modern cars, the speed of the blower motor can be adjusted gradually. The electronic module that controls the speed of the blower motor is called a blower motor control module.

What happens when a blower motor resistor goes bad?

Blower motor resistor problems. 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. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely. In most cases, a blower motor resistor fails due to corrosion or overheating.

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.