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.When the resistor goes out, you might not be able to get any air to come out of the vents. The blower motor resistor controls the power to the system’s blower motor. When it fails, it can cut off all power to the motor.
How do I know if my blower motor resistor is bad?
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.
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.
Can a bad blower motor resistor cause no heat?
The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting (4 or 5) and doesn't work at low speeds. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely.
What does the blower motor resistor do?
Blower resistors are resistors which are used to control the fan speed of automotive blowers. The fan speed can be changed either by switching the blower resistor resistance mechanically using a rotating lever, or electronically by the air conditioning system.
How do I know if my blower motor resistor is bad?
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.
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.
Can a bad blower motor resistor cause no heat?
The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting (4 or 5) and doesn't work at low speeds. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely.
Is there a way to 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.
How much does it cost to replace 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.
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.
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.
How long should a blower motor resistor last?
The blower motor resistor is designed to last for the car's lifespan. In most cases, these resistors will wear out long before the car does. Usually, the wear that the blower motor resistor has is due to the constant use that it gets and the heat that it is exposed on a regular basis.
Is there a fuse for blower motor?
What does a bad blower motor sound like?
A defective blower motor will make a continuous sound noticeable by the passengers in the vehicle. It can manifest as a knocking, whirring, clunking, vibrating, squealing, or whining noise that persists until the blower motor is replaced.
Is there a fuse for blower motor?
How do I know if my blower motor resistor is bad?
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.
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.
Can a bad blower motor resistor cause no heat?
The most common symptom of a failed blower motor resistor is when the heater fan only runs at the highest speed setting (4 or 5) and doesn't work at low speeds. In some cars, a failed blower motor resistor can cause a heater fan to stop working completely.
Where is the blower resistor located?
The blower motor resistor is usually extremely easy to access, but the hard part can be positioning your body inside the car to remove the part. The resistor is at the bottom of the HVAC housing or just behind the glove compartment.
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 long does it take to replace a blower motor in a car?
How Long Does It Take To Replace A Blower Motor In A Car? It generally takes about 4 hours for an experienced technician to do a blower motor replacement. If you are doing it on your own in your garage with common tools, you can expect the job to take 6 hours or more.
What happens when a resistor fails?
When a resistor breaks down, current typically flows through the burnt resistor without any resistance and thereby passes unchecked. Other components in the circuit may become damaged from the excess current flowing through.
What causes resistors to fail?
A fixed composition resistor normally fails in an open configuration when overheated or overly stressed due to shock or vibration. Excessive humidity may cause an increase in resistance. A variable composition resistor may wear after extensive use, and worn away particles may cause high resistance short circuits.
How do I know if a resistor is burnt?
Connect resistor to multimeter and measure voltage drop across the burnt resistor. Now measure the current flowing into the resistor. Multiply both values and you will get the wattage of Resistor (As P = VI i.e. Ohm's law). This wattage must be less than the wattage of the resistor being replaced.
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 blower motor resistor cause a fan to stop working?
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. for example, when the fan blade is jammed by foreign objects or when the motor bearings are worn out.
Why is my blower motor stuck on one speed?
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 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.
Where is the blower motor resistor on a car?
The heater blower motor resistor is often found beneath the dashboard. It is located in the heater and air conditioning compartment. It’s connected to the air conditioning system, where it can adjust the speed of the blower motor fan. It can also be found behind the glove box of some vehicles. Either way, you will find it close to the blower motor.
Is the heater blower motor resistor expensive to replace?
In the scheme of air conditioning and heater parts, this is one of the least expensive to replace. The heater blower motor resistor can often go bad because of a bad heater fan, and therefore you often have to replace both the heater blower resistor and the fan. It’s also not a difficult part to replace.
Below you will find two interesting articles on a similar topic 👇
How much is a blower motor?What happens when the blower motor on a car stops working?
