Causes of blower motor resistance failure Corrosion and Moisture: Vehicle interiors may experience moisture and humidity, which may cause corrosion on the blower motor resistor contacts or circuit boards.
The blower motor pushes air through the vents - the resistor controls the motor's speed. Sponsored by Standard. When the heat is on, your customer's HVAC system needs to be up to the task. The blower motor is like the heart of the HVAC system, pushing air through the vents to cool or heat the vehicle cabin.
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.
They fail on their own quite often. Repeated failures are typically caused by excessive current draw from the blower motor (usually caused by tight bearings), or restricted airflow past the resistor causing overheating (plugged cabin air filter, dirty heater core or A/C evaporator).
When electricity is conducted through a resistor, heat is generated and dissipated through the surrounding air. Under excessive voltage, a resistor generates so much heat that it cannot dissipate the heat quickly enough to prevent burning.
There are instances where a bad resistor will prevent the current from reaching the blower motor altogether. Without any power, the motor won't run.
Overheating is one of the most frequent occurrences that can render the blower motor inoperative. If the motor has overheated, it may shut itself down to prevent damage. You should keep your HVAC clean and clear of any blockages or debris to avoid overheating and maintain efficiency.
The average cost for a Blower Motor Resistor Replacement is between $119 and $154. Labor costs are estimated between $43 and $54 while parts are priced between $76 and $99.
If there's a power surge, then the fuse will sever the circuit and prevent the power surge from reaching the blower motor. Like any other relay, the blower motor relay regularly deals with high current loads. As a result, it can overheat and eventually melt, resulting in the relay fusing itself into the fuse box.
Your AC's blower motor is responsible for moving air through your air conditioner to cool it and then pushing it back out into your home. Without this incredible component, your AC can't provide any cooling effect, no matter how much the compressor runs.
Should I drive if my blower motor resistor is broken? You can drive, of course, but you might not be able to regulate the fan speeds in your car, which could interfere with both comfort and defrosting power.
These are different components. The blower motor high relay will affect high speed blower operation. The blower motor resistor will vary the lower speeds.
Therefore, a faulty blower motor can easily disable a fully functioning HVAC system of a vehicle. This leads to unpleasant driving experiences and uncomfortable passengers. Therefore, get the blower motor checked by a professional technician at the earliest.
If your blower fan isn't working correctly it may be because the fan resistor needs to be replaced. A replacement may cost you from $65 and go up to $375 or more, depending on your vehicle.
The blower motor resistor is designed to last till the end of the car's lifespan. However, due to multiple reasons, they tend to get damaged before. If you have a faulty blower motor resistor in your vehicle, it's best to replace it immediately.
1) A Bad Fuse
The most common reason why your blower motor won't work on any speed is that you have a bad or blown a fuse. A fuse is a small wire inside of a connector that is used to protect the motor itself from a surge of electricity.
Blower motors are designed to last just as long as your furnace itself, anywhere from 10 to 20 years. Just as with any HVAC system, the better maintained and serviced your equipment is by experienced HVAC technicians the longer it will last and the fewer repairs you'll face.
Weak Airflow from the Vents
This is usually the first indication that you may have a faulty blower motor. If the airflow coming out of the vents is weak, check the motor. It can mean that your furnace blower motor is having a hard time pushing enough air through the ducts to achieve your desired temperature.
When high speed is requested, the blower motor resistor is bypassed and the blower motor ground circuit is connected directly to ground. This allows the maximum current through the blower motor and maximum speed occurs.
Blower motor resistors have several resistors with different resistances. This controls the current that runs through the blower motor. Each fan speed selection is connected to one or more of the resistors in the blower resistor assembly.
If the resistor fails, the air conditioning and heating system may not work properly, which can affect passenger comfort.