How are the resistors on a blower motor made?
How are the resistors on a blower motor made?
Blower resistors are made of several resistors with different resistances. There are also two additional circuits used for the off state and the highest fan speed state. In the off state, the blower motor is disconnected from the power supply.
How can I tell if my blower resistor is working?
Check the fan itself for power presence by turning on the fan control and checking the fan itself for +12V at its terminals. To do this, switch your multimeter to voltage measuring mode and verify that the voltage difference between the fan’s terminals is 12V. If there is no power present at the fan, suspect a wiring fault.
How does resistance affect the speed of a blower fan?
The lower the resistance of the selected resistor in a pack, the higher the current that flows through the blower fan, and the faster the fan will turn.
How is the speed of a blower motor controlled?
This means that the current running through the blower motor, and thus is speed is controlled by the resistor value. The user chooses a suitable fan speed by using a selector to connect one of the resistors in the blower resistor pack. Blower resistors are made of several resistors with different resistances.
What does the blower motor resistor do in a car?
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. When fan speed is changed via the knob on the instrument cluster, the blower motor resistor changes setting, which changes the speed of the blower motor.
What happens when a blower resistor wears out?
The change in resistance then limits the current through the motor, which dictates the speed at which the blower fan works. Blower resistors, being a mechanical component, are prone to wear and are the most common point of failure in a car’s heating system.
How many ohms does a blower motor resistor need?
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.
What does the resistor on a heater do?
It is responsible for controlling the blower motor’s fan speed. When fan speed is changed via the knob on the instrument cluster, the blower motor resistor changes setting, which changes the speed of the blower motor.