What does the blower motor resistor do in a car?

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. 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 can I tell if my blower motor resistor is faulty?

Another symptom of a faulty blower motor resistor is no air from the vehicle’s vents at all. Power to the blower motor is fed through the blower motor resistor, so if it fails or has any issues power can be cut off to the motor.

What happens when a heater motor resistor fails?

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. 2. Blower motor does not work on certain settings

What does it mean if your blower motor is not working?

Average rating from 849 customers who received a AC is not working Inspection. 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.

Where is the blower motor resistor on a Mazda 5?

In many cars it’s fairly easy; the blower motor is located behind the glove box and held by 3-4 screws. In others it might be located inside the dash (e;g Mazda 5) which makes replacement difficult. If you need a proper diagnostic procedure, we posted several links where you can access a service manual for your car for a subscription fee.

Where is the blower motor resistor located on a Ford Escape?

In the 2008-2011 Ford Escape, the resistor is located behind the glove box on top of the HVAC unit air duct. It’s held by two screws and is easy to replace. See the photo. In the 2008-2011 Ford F150 the blower motor resistor is also located behind the glove box, but is installed in the right side of the plastic air duct.

Where does the power transistor go in a blower motor?

The power transistor has 4 wires: two come from the climate control system control unit, one is the ground, one goes to the negative terminal of the blower motor. The service manual advises measuring the voltage at the blower motor, then if not OK, at the power transistor and so on.

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.

Why does my GM blower motor resistor keep failing?

In some cases, the heat is so high that it melts the connector. This is common on late model GM vehicles. If you discover a melted connector, do NOT attempt repair. Purchase an upgraded pigtail and splice it into the harness along with a new blower motor resistor.

Why is my blower motor stuck on one speed?

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 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.

Can a broken motor switch stop a blower?

A broken blower motor switch can also stop the blower from changing to certain speed settings. If your blower motor cannot change to certain speeds, check both the resistor and the switch on your dashboard. The most common failure points are the resistor and the motor itself.

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.

What is the purpose of a blower motor resistor?

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.

Where is the resistor for the blower motor located?

Two individual resistors make up the blower motor resistor assembly on your Chevy pickup. As you’re probably already aware, these resistors are located between the A/C-Heater control panel and the blower motor . The purpose of these resistors is to reduce the amount of the blower motor’s current that’s passing through them.

Why does blower motor resistor keep going out?

The blower motor appears to be defective here. When the brushes wear out the motor draws excessive amps which could cause the resistor to burn out. Before making further replacements remove the motor and check it, especially the brush assembly. This is the most likely reason for the resistor to fail repetitively.

Is there a way to test a blower motor?

Blower Motor Resistor Testing Place one lead of the Ohmmeter on terminal 1 of the resistor. Place the other lead on terminal 2 and check against specifications. Move the lead from terminal 2 to terminal 3 and check this reading against specifications. Move the lead from terminal 3 to terminal 4 and check this reading against specifications.

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.

What are the symptoms of a bad blower motor resistor?

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

How much does it cost to replace a blower motor?

Motor type. Standard blower motors operate at a single speed and cost around $450 to replace, including parts and labor. Variable-speed motors cost $600 and up to replace.

How much does an AC blower motor cost?

The costs to replace the furnace blower motor will depend on a few factors, including the type of blower motor required, the contractor you decide to hire and your geographical region. Based on these factors, the costs, including both parts and labor, can range anywhere from $250 to more than $500 for a standard single speed blower motor.

Where exactly is the blower motor resistor?

Usually it’s located in the dashboard on the opposite side of the steering wheel. You can’t see it because it’s inside the vehicle, but that’s where it is located. The blower motor resistor is the part of the blower motor that controls the speed.

What happens when the blower resistor is bypassed?

In the off state, the blower motor is disconnected from the power supply. In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car’s battery, which allows maximum current through the motor.

How do you know if your blower resistor is bad?

Another common symptom of a faulty blower motor resistor is a a blower motor that does not function on certain settings. If the blower motor resistors’ internal components fail it may cause the blower motor to malfunction, or not function at all on one or more of the settings.

What does a blower motor resistor do?

Definition. A blower motor resistor, typically located beneath the passenger side dashboard, contains three resistors, or sets of terminals designed to generate voltage in proportion to electrical current. These resistors allow the blower motor to function at lower speeds.

What happens if the blower motor only works on high speed?

In other designs, the failure of 1 resistor means you lose only one speed. However, most car makers bypass the blower motor resistor completely when you move the fan speed switch to high. If your blower only operates on its highest speed, chances are you have the series type of blower motor resistor. This is the most common failure mode.

How many ohms does a blower motor resistor need?

According to the service manual, it must be around 4-5 ohms. In our case the ohmmeter shows open circuit, which means the resistor has failed. Sometimes, a blower motor resistor might fail due to problems with the blower motor itself.

What does blower motor resistor do?

What is the function of blower motors?

What Does a Blower Motor Resistor Do? Definition. A blower motor resistor, typically located beneath the passenger side dashboard, contains three resistors, or sets of terminals designed to generate voltage in proportion to electrical current. Function. Blower motor resistors contain controls that determine air settings. Repair.

Is the speed of the blower controlled by the resistor?

The blower speed can be adjusted in almost every modern car. Some cars have blowers that have 4 to 5 fixed speed settings that can be selected, but in this case, the speed of the blower motor is controlled by a blower motor resistor. 1. No air blowing through vehicle’s vents

Where is the fuse on a blower motor?

Locate the fuse for the blower motor in the owners/service manual. Test the fuse, with the ignition key on, using the 12-volt test light.

How does a resistor work on a blower motor?

Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch. By it’s very nature, resistors resist the flow of electricity, much like a flow restrictor in a pipe.

Where does the power go in a blower motor?

For each higher speed, power flows through one less resistor. Some car makers run blower motor power through the fan speed switch first, then through the blower motor resistor and then to the blower motor and ground. Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch.

Another common symptom of a faulty blower motor resistor is that the blower motor only works at slow-speed. This can be caused because of bad wiring between the blower motor resistor and the blower motor itself. Another symptom of a faulty blower motor resistor is that the blower motor is not able to work on some settings.

Where is the blower motor resistor located on a car?

It’s located inside the dash, often on the opposite side of the steering wheel or inside the engine compartment on the firewall. A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor.

Can a faulty blower resistor cause no air to flow?

Since the blower resistor is directly responsible to transfer the power from battery to the blower itself, a symptom of the faulty blower motor resistor is that no air flows from the car’s vent.

What does the blower motor resistor do in a car?