- Faulty Blower Motor Resistor: The blower motor resistor controls the speed of the blower motor. If it fails, the blower motor may continue to run at full speed even when the car is off.
- Malfunctioning Blower Motor Relay: The blower motor relay supplies power to the blower motor. If the relay fails, it can cause the blower motor to stay on even when the car is off.
- Problems with the HVAC Control Module: The HVAC control module regulates the climate control system, including the blower motor. If the module fails, it can send erroneous signals to the blower motor, causing it to run continuously.
- Failure of the ignition switch
Troubleshooting Steps:
1. Check the blower motor resistor. It is typically located in the passenger footwell or behind the glove box. If the resistor is damaged or has melted contacts, replace it.
2. Inspect the blower motor relay. It is usually found in the fuse box under the hood or behind the glove box. If the relay is faulty, replace it.
3. Examine the HVAC control module. It is usually located behind the center console or dashboard. If the module is damaged, it will need to be replaced.
4. Examine the ignition switch. If the ignition switch fails, it might cause the blower motor to remain on even when the ignition key is in the off position.
Note: Before performing any electrical repairs, disconnect the negative terminal of the battery to prevent electrical shock and damage to the vehicle's electrical components. If you are not comfortable performing these repairs, it is recommended to consult with a qualified mechanic or auto electrician for assistance.
