Contents
- 1 What causes a blower motor resistor to go out?
- 2 How much resistance should a blower motor have?
- 3 How do I know if my blower motor has power?
- 4 How do you test a blower motor with a multimeter?
- 5 What is a blower motor resistor and what does it do?
- 6 What should I do if my multimeter reads No current?
What causes a blower motor resistor to go out?
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 resistance should a blower motor have?
According to the service manual, it must be around 4-5 ohms. In our case the ohmmeter shows open circuit, which means the resistor has failed. Sometimes, a blower motor resistor might fail due to problems with the blower motor itself.
How do I know if my blower motor has power?
Check for power at the motor itself. Using a test light or a multimeter set on volts, unplug the blower motor. Keeping the black lead on a good ground, usually a bolt on the engine block, and the blower switch turned on, use the red lead to probe the plug that usually attaches to the blower motor.
What are signs of a bad blower motor?
Here are just a few of the signs that your blower motor is going bad.
- Weak airflow. This is one of the first signs of a bad blower motor that people tend to notice.
- Noises. Have you noticed any unusual noises coming from your vehicle’s HVAC system?
- Smoke or smells.
How do I know if my blower motor isn’t working?
What Are Signs Your Blower Motor Needs to Be Replaced?
- Poor or Airflow from Air Vents. This will be the first and most obvious sign your blower motor has a problem.
- No Airflow At All From Vents.
- Skyrocketing Energy Bills.
- Strange Noises When You Turn on the Heat.
- Overheating Blower / Weird Smells.
How do you test a blower motor with a multimeter?
Read the grounded relay with your multimeter (Ohm scale). Then check the current pin while not grounding it to the multimeter’s DC scale. If you don’t read any current, check the junction box under the hood for the IGN fuse, remove the cover panel, and using a multimeter, connect it with the negative side of your battery.
What is a blower motor resistor and what does it do?
What is a Blower Motor Resistor and What Does it Do? The blower motor resistor controls the fan speed of the blower motor and the resulting change in air pressure produced by the movement of the blower fan. It accomplishes this by regulating the electric current that powers the motor.
What should I do if my multimeter reads No current?
When your multimeter reads no current, then your blower motor is defective. If the multimeter identifies a current, then further testing of the blower motor is needed. The next thing is to remove the cover of the fuse panel access, located next to the shifter of the passenger’s side in the footwell. Take out the car’s blower motor relay.
How do you measure the voltage of a motor?
To measure the AC output voltage at either the drive or the motor terminals: Plug the black test lead into the common jack and the red test lead into the V/W jack. Select the 87V’s AC voltage function. Connect the black probe to one of the three phase output voltage or motor terminals.