Blown fuses If the blower motor relay develops any sort of problem that hinders its ability to properly limit and distribute power, it may cause the blower motor fuse to blow. Any sort of electrical spikes or excessive current from a bad relay will blow the fuse and cut power in order to protect the system.
Can a blower motor cause a blown fuse?
While the blower motor is clogged up, it can cause fuses to blow because it has to work hard to try to operate. The fuse is also attempting to run, and because it is unable, this increases the chances of a furnace fire.
How do I know if my blower motor fuse is bad?
If you hear that the blower motor is operating but don't feel any air flowing through the vents, the problem is with the airflow controls [source: RepairPal]. If the blower motor isn't running you should: Use voltmeter or ohmmeter to check for a blown fuse.
What causes blower motor relay failure?
In most cases, a blower motor resistor fails due to corrosion or overheating. Sometimes, the mechanical resistance to the motor rotation causes an excessive electric current that can overheat and prematurely damage the blower motor resistor.
Is there a fuse that controls the blower motor?
Many vehicles have two fuses for the blower motor, one in the interior fuse block and the other under the hood. The blower motor is usually under the dashboard on the passenger side.
What would cause a fuse to keep blowing?
Overloaded Circuit The most common cause of a blown fuse is when something draws too much power from the circuit. This is most often caused by either too many lights or from using too many plug-in appliances at once. The biggest culprit for this kind of issue is a multiple outlet adapter plugged into a socket.
How do you fix a fuse that keeps blowing?
Unscrew the blown fuse and replace the fuse with a new one. For circuits, flip the tripped circuit from the center position to the off position, and then flip it back to the on position. Turn the main power back on.
Where is the blower motor reset button?
Locate the reset button on the furnace and press it to reset the furnace. It is usually located inside the blower compartment on the side of the blower motor. Be cautious as the housing may be hot. If the button is popped up, press it down.
What happens when a 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.
Does a blower motor resistor have a fuse?
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.
How do I test a blower fan relay?
Connect a test light or multimeter to the ground (black lead). Turn the ignition key to the on position (engine off), and remove the relay. Using the probe, test all terminal sockets in the relay connector. Two of the four should have power.
Is there a relay for the blower motor?
In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.
Where is the blower motor relay fuse located?
Under the instrument panel, look under the glove box. On the right side of the fender wall you will find another fuse box. The blower motor fuse is easy to replace.
Why does my car heater fuse keep blowing?
Another thing that will cause your auto fuses to blow is if you insert the wrong fuses into your automobile's fuse box. Any fuse that has a higher amperage than what the circuit allows for will blow the fuse out. This, too, is a safety mechanism to prevent an electrical fire.
What would cause my heater blower to stop working?
If little air is coming through the vents (hot or cold), then it could be because the blower motor for the fan or a switch or resistor that controls fan speed isn't working. Another cause might be that the electronically controlled “blend doors” that direct air flow are stuck or broken.
What happens when blower motor resistor goes out?
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.
Where is the blower motor fuse relay?
Under the instrument panel, look under the glove box. On the right side of the fender wall you will find another fuse box. The blower motor fuse is easy to replace.
What relay controls the blower motor?
In a blower motor, the relay supplies the power that allows the fans to circulate warmed air. Essentially an on/off switch, the blower motor relay's reactions start and end the heating process in HVAC systems by controlling the flow of current between the power source and the motor.
Why does my car heater fuse keep blowing?
Another thing that will cause your auto fuses to blow is if you insert the wrong fuses into your automobile's fuse box. Any fuse that has a higher amperage than what the circuit allows for will blow the fuse out. This, too, is a safety mechanism to prevent an electrical fire.
How do I 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.
How much does it cost to replace a blower motor resistor?
How much does a blower motor resistor cost? To replace the blower motor resistor, it would cost you anywhere between $50 to$150 – this includes the cost of equipment and labor. However, by doing it yourself at home, you can save up to $70.
Where is the blower resistor located?
The blower motor resistor is usually extremely easy to access, but the hard part can be positioning your body inside the car to remove the part. The resistor is at the bottom of the HVAC housing or just behind the glove compartment.
How many blower motors are in a car?
The number of blower motors in your vehicle depends on its climate control system. Some cars have one blower motor, but that may not be the case for some SUVs and vans. They may have two motors, one in the heater box and another in the vehicle's rear area.
How do I know if my blower motor resistor is bad or blower motor?
Signs of a Bad Blower Motor Resistor Loss of HVAC fan control (total or certain speeds) The fan only works on its highest speed setting. No air coming from vents. Intermittent or inconsistent fan speed.
Will a blower motor work without the resistor?
Without any power, the motor won't run. As a result, the blower fan stays still and silent, and no air blows out of the vents. There are instances where a bad resistor will prevent the current from reaching the blower motor altogether.
How do you check a blower 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.
Below you will find two interesting articles on a similar topic 👇
How do I test a blower fan relay?How many ohms should a blower motor have?
