What happens if my blower motor relay is bad?

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.If the blower motor relay goes bad, the AC system cannot pump any heated or cooled air through the vent. The blower motor’s relay monitors the current used to power the blower motor and is continuously turned on and off. The blower motor relay will inevitably wear out over time.

How do I know if my blower 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.

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.

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 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.

How do I know if my blower 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.

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.

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.

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 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.

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.

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 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 a furnace 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.

What does a blower motor resistor do?

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 I know if my blower 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.

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.

How do you test a blower 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.

How do I know if I need a blower motor or a resistor?

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.

Should you replace blower motor and resistor at the same time?

We do suggest that you replace the resistor at the same time. It may not be critical, but this will keep the system more uniform. The issue may even be related to the resistor. If you know that it is not related to the issue, then you do not have to replace it.

Why is my blower not working in my car?

Find the fuse associated with the A/C blower motor. If the blower motor fuse is still in-tact, your problem is located elsewhere. If the fuse is blown, simply replacing the fuse with an identical fuse of the same amperage rating could get your system working again!

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.

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.

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.

Does the blower motor resistor control heat?

The blower motor resistor is an electrical component that is a part of the vehicle's heating and air conditioning system. It is responsible for controlling the blower motor's fan speed.

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.

Why does my AC blower motor relay keep blowing?

One of the first symptoms of a bad or failing AC blower motor relay is a blown AC blower motor relay circuit fuse. 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.

What are the symptoms of a bad blower motor relay?

When the blower motor relay does begin to fail, the vehicle will usually display a few symptoms that alert the driver of a potential problem that should be serviced. 1. Blower motor does not function One of the first symptoms of a problem with the blower motor relay is a blower motor that does not function at all.

Should I repair or replace my blower motor relay?

Any blower motor relay problem should be diagnosed and fixed only by a specialist or authorized contractor. Do not perform any replacements or repairs if you do not have enough knowledge about HVAC systems, as this could cause further problems. Mike Kelsen Recent Posts link to Diagnosing Damper Issues: Residential Airflow Balancing & MORE

What to do if your blower motor is not working?

The faulty blower motor relay is disconnected, or the socket is taken out of the relay. The link or socket will undergo a test for disruption. If there is no damage, they will attach the new blower motor relay.