Since it directly contributes to airflow, a bad blower motor resistor will affect your HVAC system's ability to both heat up AND cool down. If your fan seems to work properly, the speed settings function, and air is moving fine, but it's just not getting cold, then you may have a bad heater core.
Comments Section Resistor will usually work on low or full power, blower motor won't work on any. Turn the blower on high and give the area where the motor is a bit of a smack. If it starts spinning, you need a new motor. If it doesn't, get out that DVOM and start checking for power.
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.
Symptoms of a bad blower motor resistor that you may experience are the blower motor only working on higher speeds, no air coming from the vents, the blower motor stuck on a single speed, and the blower motor working on some speeds and not others. Thank you for watching!
Checking a Resistor
Turn off power to the resistor and disconnect it from the circuit. Then, connect the 2 leads on a multimeter to the 2 legs on the resistor. Also, look for signs of damage on the resistor, like blackening or charring.
You can still drive your car despite a faulty blower motor resistor. However, you'll probably find it uncomfortable to have the blower running at one speed setting the entire time or having limited access to certain settings.
Normal wear and tear: Like all mechanical and electrical components, blower motor resistors wear out over time. Repeated heating and cooling cycles and the mechanical stress associated with adjusting fan speeds can cause it to gradually degrade.
Since it directly contributes to airflow, a bad blower motor resistor will affect your HVAC system's ability to both heat up AND cool down. If your fan seems to work properly, the speed settings function, and air is moving fine, but it's just not getting cold, then you may have a bad heater core.
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.
Symptoms of a Bad Blower Motor Relay
On platforms where the blower is directly controlled by the switch rather than a module, the relay will cause the blower not to work at all, which means there will be no airflow across the evaporator, and the effect will be the same as the A/C not working at all.
Premature resistor failure can result from a failed blower motor.
A defective ground wire or ground wire connection and an open circuit in the power-side circuit (including the fuse, wiring, and fan switch) are the most common reasons why a blower motor fails.
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. When the blower motor doesn't get power, air pressure can't be produced. You are left with a heater or air conditioner with nothing coming out of the vents.
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.
Auto Heater resistor: how much does this product cost? The price of car parts within the auto Heater resistor category ranges from £9 to £45, depending on the vehicle type, manufacturer, and product specifications.
If it is badly plugged up it will restrict airflow and cause overheating of the resistor. The usual failure mode of the resistor is the thermal fuse built into it will open. This could also be caused by bad bearings in the motor which will result in excess current and heat.
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.
In general, the parts themselves usually cost between $20 and $100. Labor costs for installation range from $50 to $200, depending on the complexity of the installation and the mechanic's labor rate. Therefore, the total cost can range from $70 to $300.
SMOKE OR SMELL WHEN DRIVING
In that case, immediately pull over. A burned blower motor cannot exactly damage your car but you are not sure that the smoke is coming from the blower motor. Such signs indicate damage and you must tow it to a mechanic before turning the engine back on.