How does a resistor work on a blower motor?
Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch. By it’s very nature, resistors resist the flow of electricity, much like a flow restrictor in a pipe.
Why does my GM blower motor resistor keep failing?
In some cases, the heat is so high that it melts the connector. This is common on late model GM vehicles. If you discover a melted connector, do NOT attempt repair. Purchase an upgraded pigtail and splice it into the harness along with a new blower motor resistor.
Where does the power go in a blower motor?
For each higher speed, power flows through one less resistor. Some car makers run blower motor power through the fan speed switch first, then through the blower motor resistor and then to the blower motor and ground. Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch.
Can a blower motor relay be a problem?
One of the first symptoms of a problem with the blower motor relay is a blower motor that does not function at all. As the relay is the switch that supplies current to the blower motor, if it fails internally, then power will be cut off from the blower motor circuit, causing the motor to no longer function or blow any air from the vents.
What happens when a blower motor resistor fails?
The blower motor resistor is the component directly responsible for controlling the blower motor fan speed. If the resistor shorts or fails, it may cause the blower motor to remain stuck on one fan speed.
What are the symptoms of a bad heater motor resistor?
Symptoms of a Bad or Failing Heater Blower Motor Resistor. 1 1. Blower motor stuck on one speed. A common symptom of a faulty blower motor resistor is a blower motor that is stuck on one setting. The blower 2 2. Blower motor does not work on certain settings. 3 3. No air from the vehicle’s vents.
For each higher speed, power flows through one less resistor. Some car makers run blower motor power through the fan speed switch first, then through the blower motor resistor and then to the blower motor and ground. Other car makers reverse that and run power to the blower motor first and terminate ground at the blower fan speed switch.
How to replace the blower motor resistor on a Ford Focus?
Remove the wiring harness retainers, the nuts and the BCM bracket. Disconnect the air inlet door actuator electrical connector, and remove the front air inlet duct retainer. Install the ratchet, extension and socket as shown. Remove the upper air inlet duct retainer. Disconnect the electrical connector.