How do you remove a blower motor resistor?
Carefully lift the glove box out from under the dash and set it aside. Remove the screws that secure the blower motor resistor to the housing, and put them someplace safe. At this point, you can remove the resistor from the housing. Disengage the wire harness locking tab, and disconnect the wire harness from the blower motor resistor.
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.
Why are there so many resistors on a blower switch?
The blower switch and its gang of resistors are wired so that when the blower switch is set at the lowest speed, the maximum amount of voltage is dropped and the least amount of current is fed to the motor because it is passing through an entire series of resistors – for our purposes we’ll say there are three resistors.
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.
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.
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 is an AC resistor?
Resistor AC Response. For ordinary currents and frequencies the behavior of a resistor is that of a dissipative element which converts electrical energy into heat. It is independent of the direction of current flow and independent of the frequency. So we say that the AC impedance of a resistor is the same as its DC resistance.
What kind of resistor does a blower fan use?
The newer style of blower resistor uses electronics to send small pulses to the blower motor and based on how frequent the pulses are can speed up and slow down the blower fan. Blower motors can be fairly cheap if they are a manual resistor block style.
When do I need to replace my blower motor?
However, a weak blower motor can place an excess load on the controller. If there are any signs of a failing blower motor (such as noisy operation or a slow turning blower), it should be replaced as soon as possible to prevent burning out the speed controller by drawing excess current through it.
Why does my blower only work on high speed?
On an older style HVAC system with manual controls, the most common symptom of a failed blower motor resistor is that the blower only works on high speed. This is because if the resistor overheats and melts on the resistors in the block, it will cause the blower resistor to open.
How much does a blower motor cost?
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. If a blower motor is required for a more expensive unit, such as a variable-speed motor, then the costs could be more than $1,000; however, these motors tend to be relatively rare.
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.
Always disconnect negative battery terminal. Remove the blower motor resistor retaining screws. Remove the blower motor resistor. Install the blower motor resistor retaining screws. Tighten the screws to manufacturer specifications. Connect the electrical connection to blower motor resistor. Connect the electrical connection to blower motor.
How does change in resistor affect speed of blower motor?
By changing the resistance in the circuit, the voltage and current are affected as well. Resistance decreases and current increases as the selector is moved from Low to Medium to Medium-High. This increase in current as the resistor moves toward higher speeds increases the speed of the blower motor.
What causes a blower motor to heat up?
Heat either caused by poor airflow across the resistor pack resulting in poor cooling, or heat caused by a higher amperage draw from a worn out motor with poor lubricated bearings/bushings or worn brushes. If the motor was serviceable, that would be the next route I would take.
How to replace a fuse on a blower motor?
Use a die grinder or equivalent to remove the original crimps down to where the lead breaks in two and the fuse will fall off. Use the pointy end of the grinder bit to just carefully drill the rest of the material out and take a bit of the galvanized surface down to clean metal. I suppose you could use a small drill bit for this step too.
What happens when a blower motor resistor is bad?
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. Resistors have it rough.
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.
Do you have pictures of the blower resistor location?
Do you have pictures of the blower resistor location? It is not a resister pack as it use to be in the older vehicles. It is basically a FET transistor that varies the voltage to the blower motor. The blower control module is on the back side of the HVAC box next to the firewall.
Where can I find blower motor speed control?
It was under 412-01 Climate Control – Blower Motor Speed Control. From there it will link you to all the relevant sections. There are also some good exploded views that you should have handy.
What should the resistance of a blower motor resistor be?
For example, in this photo we measured the resistance of this blower motor resistor. 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.
Why is my heater blower resistor not working?
It is also possible that the heater motor blower may not work at all. If the resistor has gone bad, it is likely that the fan will work only on the highest speed. *If no air is coming out of your vents, you may have a problem with the heater blower motor as well as the resistor.
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 blower motor resistor located?
The blower motor resistor is located under the dash on the right hand (passenger) side. It’s near the firewall, just below the windshield.
Carefully lift the glove box out from under the dash and set it aside. Remove the screws that secure the blower motor resistor to the housing, and put them someplace safe. At this point, you can remove the resistor from the housing. Disengage the wire harness locking tab, and disconnect the wire harness from the blower motor resistor.
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.
When do you need to replace the fan resistor?
If your interior AC/ Heat fan is not working on low, or one of the fan settings is not working, then you probably need to replace the blower motor resistor. This video will go though all of the steps. Is your blower fan working only on the max (4 speed)? This is a common problem with the Volkswagen, Audi, Seat, Skoda cars.