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The blower motor resistor is responsible for controlling the blower motor speed. Each fan speed selection is connected to one or more of the resistors in the blower resistor assembly. The change in resistance controls the current through the blower motor, which in turn limits the speed that the blower motor spins at.
What happens when blower motor resistor goes bad?
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.
How do I know if my blower motor resistor is bad?
Bad Blower Motor Resistor Symptoms Only One Speed From Blower Motor. One of the most common symptoms of trouble with the blower motor resistor is when the fan gets stuck in one setting. Various Airflow Settings Not Working. No Air Coming From Vents.
What are the symptoms of a bad blower motor?
SIGNS OF A BAD BLOWER MOTOR FAN BLOWS AT ONLY A CERTAIN SPEED. WEAK AIRFLOW OF THE BLOWER MOTOR. UNUSUAL NOISES FROM HVAC SYSTEM. SMOKE OR SMELL WHEN DRIVING. HOW DOES A CAR BLOWER MOTOR WORK?.
Why does my blower motor resistor keeps melting?
Trent, one of the biggest reasons for blower motor resistors to have shorten life is actually because of faulty blower motor drawing too many amps, some times melting wires/plugs, heating up resistors shortening their life. Many Dodge forums tell of this problem.
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.
Can you fix a blower motor resistor?
The average cost to replace the blower motor resistor at a repair shop is between $44 and $55 in parts and $70 in labor costs, for a total cost of around $114 to $125. On the other hand, you can easily fix the blower motor resistor at home in about an hour (even if you’re a beginner) and for around $70.
Why does my blower motor only work on high?
Most car manufacturers use a series of resistors to make the heater blower motor run at different speeds. And when one or more of these resistors burn out, you’re usually left with only one heater blower motor speed—high. The resistor module is easy and inexpensive to replace.
Why is my blower fan not working?
Make sure that the power cord hasn’t melted or a fuse hasn’t been blown. If your cables are looking fine, try unplugging the fan for a few minutes and then plugging it back in again. If unplugging and plugging your fan back in again doesn’t work, check the fuse box.
What does it sound like when your blower motor goes out?
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.
Why is my blower motor so loud in my car?
Loud noises you hear when your car’s heater or air conditioner are on typically indicate a blower motor issue. The good news is that a blower motor problem like this can be the result of something as simple to fix as debris or trash that got caught in it.
Can a blower motor resistor be bypassed?
Blower resistors are made of several resistors with different resistances. In the highest speed state, the blower resistor is bypassed completely and the fan is connected directly to the car’s battery, which allows maximum current through the motor.
Do blower motor resistors get hot?
Yes, it would get hot, but the resistor(s) are often mounted in the air duct near the blower, so the air stream would cool them. If it were outside the air stream or if the air were blocked it would definitely get hot.
What would cause a resistor to burn up?
Burning of Resistor When a resistor has been overloaded with voltage exceeding its power rating, the resistor will become very hot to touch, darken considerably and possibly even melt or catch on fire. Although a resistor may appear damaged at this point, it can still be functioning.
Why does my blower motor keep running?
Well, if your furnace blower fan won’t stop running, you could have any of the following problems: You’re using the wrong thermostat fan setting. There’s a shorted thermostat wire. There’s a shorted wire at the fan limit switch.
Can you drive a car without a blower motor?
Your car’s blower motor is not only necessary for the operation of your air conditioner. Without a functioning blower motor your engine runs the risk of overheating. Start car and see if blower motor works. If fuse blows again, check for loose circuits.
Are all blower motor resistors the same?
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.
How long does it take to replace a blower motor resistor?
takes about 45 minutes.
Why does my AC only work on Max?
The blower motor resistor is prone to shorts, corrosion, and overheating. When the resistor fails, typically, the highest setting is the only option that still functions. This is because the air from the blower motor is bypassing the resistor, thus gaining the maximum amount of voltage, resulting in full power.
