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 a blower 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.
How can you tell if a fan relay is bad?
Symptoms of a Bad or Failing Cooling Fan Relay
- Engine running hot. One of the first symptoms commonly associated with a bad or failing cooling fan relay is an engine that runs hot or overheats. …
- Cooling fans do not function. …
- Cooling fans stay on at all times.
Why does my blower motor fuse keep blowing?
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.
What can cause a blower motor to stop working?
In a situation where the motor doesn’t work on any speed, the most likely causes are: a blown power supply fuse, a bad motor ground connection, bad motor speed control module or a failed motor. On all systems, a failed blower motor is least likely.
Why does my blower motor resistor keeps going bad?
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 you drive a car without a blower motor?
Your car’s blower motor is not only necessary for the operation of your air conditioner. Without a functioning blower motor your engine runs the risk of overheating. … Start car and see if blower motor works.
Can you drive a car with a bad blower motor?
A bad heater blower motor will not affect the safety of your car, with the possible exception of you not being able to clear the windshield of snow, ice, or condensation if the defrosters don’t work. But you won’t be comfortable inside your car, especially during the cold of winter and the heat of summer.