Why is my HVAC running when thermostat is off?
If your AC system short circuits, the commands you enter at your thermostat likely aren’t getting passed onto your system. So, if you turn your AC “off” at your thermostat, that command isn’t registering with the fan or cooling system, causing your AC to stay on when you’ve told it to shut off.
Why does my car blower motor not shut off?
If you have a vehicle with climate control system and a variable speed blower motor and the blower motor won’t shut off and stays on HIGH with the car turned off and the key out, chances are the blower motor motor control processor is toast or the HVAC control module is damaged.
Why does my rear AC blower keep spinning?
But #36 looks like it would stop it only if the HVAC CM-Aux was the fault. If you pull #36 and it keeps spinning then it is the BMCP-Aux. The blower motor control processor controls the speed of the blower motor by increasing or decreasing the voltage drop on the ground side of the blower motor.
How does the HVAC work on a blower?
The HVAC control module provides a low side pulse width modulated signal to the blower motor control processor over the blower motor speed control circuit. As the requested blower speed increases, the HVAC control module increases the amount of time that the speed signal is modulated to ground.
How is the speed of the blower motor controlled?
The blower motor control processor controls the speed of the blower motor by increasing or decreasing the voltage drop on the ground side of the blower motor. The HVAC control module provides a low side pulse width modulated signal to the blower motor control processor over the blower motor speed control circuit.
If you have a vehicle with climate control system and a variable speed blower motor and the blower motor won’t shut off and stays on HIGH with the car turned off and the key out, chances are the blower motor motor control processor is toast or the HVAC control module is damaged.
But #36 looks like it would stop it only if the HVAC CM-Aux was the fault. If you pull #36 and it keeps spinning then it is the BMCP-Aux. The blower motor control processor controls the speed of the blower motor by increasing or decreasing the voltage drop on the ground side of the blower motor.
The HVAC control module provides a low side pulse width modulated signal to the blower motor control processor over the blower motor speed control circuit. As the requested blower speed increases, the HVAC control module increases the amount of time that the speed signal is modulated to ground.
How does a blower motor controller work on a car?
It’s really a simple concept: the blower motor controller pulses either the power or the ground circuit on and off depending on which fan setting you choose.