The blower motor relay controls the current used to power the blower motor, and is subject to the constant on and off switching.
Where is the blower motor relay?
The blower motor relay is generally located in the under-hood fuse box or in the under-dash fuse box. A blown fuse can mimic relay failure. A failed blower motor switch can also give many of the same symptoms.
What does the blower relay control?
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.
What controls the blower motor on a car?
Blower resistors are resistors which are used to control the fan speed of automotive blowers. The fan speed can be changed either by switching the blower resistor resistance mechanically using a rotating lever, or electronically by the air conditioning system.
How do you test a blower motor relay switch?
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.
What does the blower relay control?
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.
How do I know if my blower motor relay is bad?
If you have a faulty blower motor, you may experience low airflow from the vents, even when the fan is on high. There will be no air coming from the vents if your fan isn't working due to a bad blower motor resistor. Blown relay circuit fuses or melted relays are more serious signs of a bad blower motor relay.
Does a blower motor have a relay?
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 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.
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.
Where is the blower motor control module?
It's located inside the dash, often on the opposite side of the steering wheel or inside the engine compartment on the firewall. A blower motor resistor or a blower motor control module is the part that controls the speed of the blower motor.
Why does the blower motor stopped 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.
How do I know if it's my blower motor or resistor?
Typically, if the fan will work on some speeds but not on others, the resistor is suspect. Okay, let's say there's no melting going on, but your fan doesn't work on all speeds. Typically, if the fan will work on some speeds but not on others, the resistor is suspect.
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.
What controls the blower motor on the furnace?
A fan limit switch is a component of a furnace system that determines when the furnace blower assembly for hot air turns on and off. Essentially, this means that it determines when the hot air should be blown through your ventilation system. The fan limit switch also has two other functions.
Which fuse is the blower motor fuse?
What controls the blower motor on the furnace?
A fan limit switch is a component of a furnace system that determines when the furnace blower assembly for hot air turns on and off. Essentially, this means that it determines when the hot air should be blown through your ventilation system. The fan limit switch also has two other functions.
What does the blower relay control?
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.
How do you test a blower motor relay switch?
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.
How much does it cost to replace a blower motor relay?
The blower motor is operated by an electrically operated switch, called a relay. If the relay fails, the motor's fans will not blow conditioned air into your car. Fixing the relay usually costs around $50 to $80. So, if the blower motor relay fails, you could be left sweating or shivering.
How do you check a relay?
The only tool required to check a relay is a multimeter. With the relay removed from the fuse box, the multimeter set to measure DC voltage and the switch in the cab activated, first check to see if there are 12 volts at the 85 position in the fuse box where the relay plugs in (or wherever the relay is located).
How can I tell if a relay is bad?
You want to feel and listen for any clicks. If you feel and hear clicks, the relay works on one side – the side with the energizing circuit and coil. However, if there was no sound from the horn, the relay has a problem along the contact circuit.
Why is my car heater fan not working?
If the heater isn't blowing hot air at you when you turn the system on, the blower fan might have a problem. Either it's not getting electrical power or, more likely, the motor itself has simply burned out. A blower motor in an older vehicle is likely to burn out over time, and may need replacement.
Which fuse controls heater in car?
The blower fuse is a 40 amp fuse located in the engine compartment's fuse box.
What does a heater relay do?
The electric relay in a furnace is responsible for relaying electrical power to the heating elements and the blower motor inside the furnace cabinet. The heating elements provide the heat to warm the air, and the blower motor sends this warmed air through the ductwork.
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 does a blower motor relay do on a car?
Blown fuses 3. Melted relay The blower motor relay is the electrical switch that is used to supply the power for the vehicle’s blower motor. The blower motor is the component responsible for pushing air through the vents of your vehicle’s heating and air conditioning systems.
What causes a blower motor to stop working?
Since the relay supplies the current that makes the motor move, a nonresponsive motor may be the result of a worn out relay. The blower motor relay does more than channel electrical current.
What kind of power does a blower motor control module use?
For example, in the mentioned 2009 Honda Accord, the + 12V power is supplied directly to the blower motor through the fuse and then through the relay. Testing Honda power transistor (blower motor control module). The blower motor control module (Honda calls it Power Transistor) supplies the ground.
How does a blower motor resistor work?
The blower motor resistor works by controlling the speed of the blower motor. Previously, this control was simply done by changing the supplied voltage toward the blower motor. At present, this resistor is used to transmit a varied signal toward the motor. This resistor is inbuilt with different resistors including different resistances.
Below you will find two interesting articles on a similar topic 👇
What happens if your blower motor relay is bad?How do I know if my AC blower fuse is bad?