Blower motor resistor melted, replaced it turned on blower motor and it melted again in seconds.
What would be causing this to happen? I plan on replacing both the blower motor and the blower motor resistor. Would there be anything else i need go look into as well?
My car has 124000 miles.
My car has an automatic transmission.
Experienced mechanics share their insights in answering this question :
The blower motor that is drawing too many amperes will melt the resistor and wiring. Anytime the resistor is melted you should replace the blower along with the resistor and connections that show any heat damage. If you need assistance with this, consider YourMechanic, as one of our mobile technicians can diagnose electrical issue and help you replace the blower motor and resistor as necessary.
How to Identify and Fix Common car Problems ?
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The blower motor that is drawing too many amperes will melt the resistor and wiring. Anytime the resistor is melted you should replace the blower along with the resistor and connections that show any heat damage.
A typical reason for your blower motor overheating is a clogged air filter. When the air filter is clogged, the blower motor has to work harder to pull warm air into the system, which can cause the motor to overheat. To keep your fan motor from overheating, you`ll want to check your air filter every 2 months.
There could get a few causes: if the blower is pulling too much current, perhaps because of worn bearings or if it`s jammed, or perhaps the coolant is going over temperature, or perhaps the thermal fuse failed inappropriately.
Lack of maintenance: This is probably the most common reason that causes condenser fan motors to overheat and shut off. Proper and regular lubrication of the fan motor is necessary for the motor to run smoothly. Periodically making sure that there`s no debris or dust in or around the fan motor is also a good idea.
If a resistor`s temperature keeps rising, the material within eventually reaches its melting or vaporization point. Poof! The resistor burns itself out and becomes an open circuit. At any point of localized overheating (or weaker material), the loss of material causes an increase in the local resistance.
Because resistors impede the flow of current, they generate heat. If the resistor operates within its power rating, the heat is harmlessly dissipated into the surrounding environment. But, if we exceed the wattage rating, the resistor cannot dissipate the excess heat, and its temperature rises.
Replacing the capacitor and/or fan blade with the correct one should solve the problem. Poor airflow. Not having the fan blades installed in a correct position can result in a lack of airflow and cause the motor to overheat.
Inconsistent blower motor operation
If the capacitor is bad, the blower motor may run slowly or inconsistently, or overheat easily. If you notice that your blower motor works strangely or short cycles, make sure to contact professionals to inspect your capacitor.
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.
A fuse is often located on the resistor board. The fuse only protects the low and medium blower speeds. High speed will still work if the resistor fuse is blown.
Reduce the power dissipation: One of the simplest ways to reduce the heat generated by a resistor is to reduce the power dissipation. This can be done by reducing the voltage or current flowing through the resistor or by increasing the resistance value of the resistor.
Reduce the power dissipation: One of the simplest ways to reduce the heat generated by a resistor is to reduce the power dissipation. This can be done by reducing the voltage or current flowing through the resistor or by increasing the resistance value of the resistor.
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.
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.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
Blower motor resistor melted, replaced it turned on blower motor and it melted again in seconds.
ANSWER : The blower motor that is drawing too many amperes will melt the resistor and wiring. Anytime the resistor is melted you should replace the blower along with the resistor and connections that show any heat damage. If you need assistance with this, consider YourMechanic, as one of our mobile technicians can diagnose electrical issue and help you replace the blower motor and resistor as necessary.
Burnt yellow and brown wires at blower motor resistor, is this indicator of bad resistor or bad motor? 2011 Chevrolet Malibu
ANSWER : Hi there – most likely, the problem is the blower motor resistor pack. A quick way to test this is if the blower fan still works in the "Max" position. If it does, that pretty-much rules out the motor as the problem. The resistor pack can get pretty hot while running the fan in lower settings, which could damage the wiring to it just from the heat. If the resistor shorts, increased electrical load could burn the wiring insulation as well. I would suggest an electrical inspection by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, give you an accurate assessment of damage and cost estimate for repairs.
Heater blower stuck on high and will not turn off unless igniton is off
ANSWER : This suggests that the relay may be supplying power to the blower motor regardless of turning the switch off. The blower motor relay supplies power to this motor when you turn the switch to "on" that can sometimes fail. When this happens, you may notice that you will not feel anything blowing out of the vents at all. This may also cause the blow motor to work intermittently. I would suggest having an expert from YourMechanic come to your location to diagnose your vehicle’s blower motor system.
If I get my blower motor replaced, do I also have to have my Ac recharged after replacing blower motor?
ANSWER : The blower motor on this vehicle is a simple removal and installation and does not require anything to be touched on the A/C. The refrigerant does not have to be removed. The only component that has to be removed is the glove box under cover to get to the blower motor.
Car A/C won’t stop blowing even with car turned off, can I unplug blower motor resistor ?
ANSWER : Yes, you can disconnect the resistor or the blower motor to stop the power drain. You can do this until you can get it fixed anyway.
Is a transistor and a blower motor resistor the same thing?
ANSWER : When you were told to replace the resistor or the transistor the person that told you did not know if you had manual or automatic a/c. Your car will have a blower resistor for manual a/c blower controls and a transistor if you had automatic a/c controls. Your blower control is manual and therefore you have a blower resistor. The car will only have one or the other and will serve the same purpose depending on the type of blower control you have. The squeaking and burning smell may be from the blower motor. I would recommend replacing the blower motor with resistor(https://www.yourmechanic.com/services/heater-blower-motor-resistor-replacement) This should fix your problem and do not have to replace blower transistor since your car does not have one.
My Blower motor is not blowing even after I’ve replaced it and the resistor.
ANSWER : Occasionally, the blower motor itself will wear out or become faulty working intermittently as the brush contacts inside the motor wear out. The blower motor relay supplies power to this motor when you turn the switch to "on" that can sometimes fail. When this happens, you may notice that you will not feel anything blowing out of the vents at all. This may also cause the blower motor to work intermittently. I would suggest having an expert from YourMechanic come to your location to diagnose your vehicle’s blower motor system.
Loss of voltage at blower motor when it is connected to regulator – regulator is brand new
ANSWER : Hi there. The issue you are having is not the resister, but rather the switch. The switch contacts are shorting out back to the battery causing the a/c blower not to work. I recommend replacing the a/c blower switch. If you need further assistance troubleshooting your vehicle, then seek out a technician, such as one from YourMechanic, that can assist you with replacing the switch.
