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.
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.
How do you test a blower motor 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.
What does blower motor relay do?
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 are the signs of a bad blower motor?
You might also hear ongoing whirring noises, or noises that change or get louder if you increase the fan speed. These are all signs of problems with the blower motor. In some cases, you may even notice smoke or smells of burning while driving, in which case you should pull over immediately.
What can cause a blower motor to stop working?
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.
Can AutoZone test a relay?
If something within your electrical system seems to be faulty, inspect your relays first.
Why is my car not blowing air at all?
Your air intake is clogged, meaning that air isn’t getting in from the outside at all or isn’t circulating properly. There is a blown fuse in the ventilation system. Electrical issues such as a bad relay. Damaged blower motor.
Is there a fuse for blower motor?
To protect the blower motor power circuit, a 20-, 25- or 30-amp fuse is usually located in the fuse panel under the dash. The rating of the fuse will depend on the vehicle application and how much power the blower motor requires at full speed.
How much is a blower motor relay?
The average cost for blower motor relay replacement is between $73 and $82. Labor costs are estimated between $35 and $44 while parts are priced at $37.