To quickly pinpoint whether the issue is the blower motor or the resistor, check the fan speeds. If the motor only works on the highest setting, or behaves erratically, the resistor is likely bad. If the motor does not work on any speed, the blower motor itself may be failing.
Replacing a blower motor resistor typically costs between $90 and $300 for parts and labor. The part alone runs about $20 to $100, while labor takes a mechanic 30 to 90 minutes, adding another $50 to $200 depending on your vehicle's make and model.
Which one to replace? If high setting works and medium and low do not, replace the resistor. If blower motor is spinning but makes noise, replace the blower motor. If you hear noise and only high setting works, replace both.
Blower motor resistors typically last between 5 to 10 years. However, there is no set mileage or exact expiration date. Their actual lifespan heavily depends on usage, the quality of the part, and whether your cabin air filter is regularly changed.
The labor cost to replace an HVAC blower motor typically ranges from $150 to $400, depending on your location and the complexity of the job. This generally accounts for 2 to 3 hours of work at a standard hourly rate of $75 to $150.
As we know, the resistor is responsible for controlling the blower motor's speed by regulating the voltage supplied to it. It will turn out that without the resistor, the blower motor may run at maximum speed or not function as expected.
The heat exchanger is often considered the most costly part of a furnace to repair or replace. It is a critical component that transfers heat from the combustion process to the air that circulates throughout your home. Over time, heat exchangers can crack due to the constant heating and cooling cycles they undergo.
When a resistor goes bad, its internal resistance changes. It will generally either fail open (stop the flow of electricity entirely) or drift in value (block too much or too little current). This can cause the circuit to malfunction, overheat, or fail completely.
Blower motor replacement typically takes 2 to 3 hours, depending on the system's complexity and accessibility. Simpler replacements, such as for standard systems, may take around 2 hours, while more complex systems, especially those with harder-to-reach motors, can take 3 hours or more.
The best aftermarket blower motor brands are JC Whitney, GPD, 4-Seasons, Replacement, Continental, and VDO. When buying cooling blower motors, consider application, quality, cost, customer reviews, and brand reputation.
This usually means a bad capacitor, blower motor, or thermostat issue. Can I run my furnace without the blower? No. The furnace will overheat and shut down for safety.
A bad blower motor—whether in your car or home HVAC system—struggles to push air effectively. Common symptoms include weak or no airflow from the vents, abnormal noises like grinding or squealing, strange burning smells, and a fan that works intermittently or stops entirely.
To test a blower motor resistor, set your multimeter to measure resistance (Ohms). Disconnect the resistor and measure the resistance between the common input pin and each speed pin. If you read "OL" (Open Line) or zero resistance, the resistor or its thermal fuse is blown and needs to be replaced.
The primary causes of a blower motor resistor failure are overheating and corrosion. Because the resistor regulates fan speed by converting excess electrical energy into heat, it relies on the HVAC airflow to cool down. Common triggers include restricted cabin air filters, failing blower motors, or moisture buildup.
A furnace typically lasts between 15 and 20 years. However, the exact lifespan varies based on the type of unit and how well it is maintained.
The $5,000 rule is a guideline to help homeowners decide whether to repair or replace their HVAC system. You multiply the age of your unit by the cost of the needed repair. If that number exceeds $5,000, replacing your HVAC system is often more cost-effective.
Capacitors are used in nearly every heating system, from gas furnaces to electric furnaces to heat pumps. Even though other parts can fail, like the ignitor in a gas furnace or the compressor in a heat pump, the capacitor is by far the most common part to fail on a furnace because almost every system relies on one.
Diagnosing a faulty blower motor versus a bad resistor typically comes down to what fan speeds are working. If the fan only works on the highest setting, the resistor is usually the culprit. If the fan doesn't work on any speed, or if it makes strange noises, the motor itself is likely failing.
The blower motor reset button is usually a small, red or yellow button located directly on the motor housing, inside the blower compartment of your air handler or furnace.
Replacing a blower motor resistor typically costs between $90 and $300 for parts and labor. The part alone runs about $20 to $100, while labor takes a mechanic 30 to 90 minutes, adding another $50 to $200 depending on your vehicle's make and model.
While a fan stuck on high is the most common indicator, a complete loss of fan function on all settings can also point to a failed resistor. In some cases, the entire component can fail catastrophically, often due to a significant electrical surge or extreme heat.
One of the most frequent errors when using a multimeter is not selecting the appropriate measurement range. Multimeters have various ranges for voltage, current, and resistance, and using the wrong range can lead to inaccurate readings or even damage the multimeter.
Resistors most often fail open, not closed as in a short circuit. So if you just wanna take a quick and dirty look, you can place a resistance meter across the component and you should get the resistor's rated value OR LESS.