Symptoms Of a Bad Blower Motor Resistor

A blower motor resistor, to put it simply, is an electrical component that has the ability to prevent current from entering the blower fan motor. By increasing the resistance, the fan won’t spin as quickly, which reduces the amount of hot or cold air that is circulated around the cabin. You can alter the path that energy takes via the blower motor resistor on its way to the blower motor by turning the fan speed knob from one setting to another.

The blower motor may become stuck at one speed when the resistor fails. You might also experience problems with the different airflow settings or have no air coming from the vents. Additionally, it may result in variable or sporadic fan speed, depriving you of adequate airflow.

Well, in this article, I’ll be discussing the symptoms of a bad blower motor resistor.


What are the symptoms of a bad blower motor resistor?

symptoms of a bad blower motor resistor

Various airflow settings not working

On the other side, you can discover that the fan only functions in some settings. The blower motor resistor is not required when the system is turned off. When the blower motor is set to run at full speed, this is also accurate. The resistor is necessary to regulate the flow in the other settings, though. Having said that, the blower motor switch may also be to blame for this condition. As a result, you might need a second diagnosis to identify the problematic component.

Blower Motor Only Works on One-Speed

The majority of modern heaters and air conditioners have adjustable fan speeds. The fan’s setting needs to be simple for you to select. However, the blower motor becoming stuck on one setting is one of the most typical signs of a faulty blower motor resistor. The resistor can be an issue if you are unable to remove the motor from a high or low position.

No air coming from vents

You might not be able to get any air to come out of the vents when the resistor fails. The blower motor resistor regulates the power going to the blower motor in the system. It may shut off all power to the motor if it malfunctions. Air pressure cannot be produced if the blower motor is not powered. The only thing left is a heater or air conditioner with no air escaping the vents.  If nothing is coming out of the vents, there are other things you would want to check before the resistor. If nothing is functioning, you ought to start by checking the fuses. From here, you might also assume that the blower motor has stopped working altogether.

Intermittent Or Inconsistent Fan Speed

You may only be able to get one option or a specific speed to operate, as we’ve already explained. However, there is also a chance that the system will occasionally go wrong. As a result, it’s possible that you have excessive air pressure for a minute before it stops. These irregular problems point to an electrical issue or a problem with the blower motor resistor.

Related Article:


HVAC fan speeds in a vehicle’s temperature control system may be inconsistent or non-operational due to a broken blower motor resistor. This problem may make it difficult to control the cabin’s airflow and temperature, which will be uncomfortable and diminish the efficiency of the climate control.

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