Blower Motor Speed

WARNING: This page is about a different car, the 2012 Ford Flex. However, it is still accessible from the selected car via links, so may be relevant.

The blower motor speed control controls the blower motor speed by converting low power signals from the HVAC module to a high-current, variable ground feed for the blower motor. The HVAC module adjusts blower motor speed based on the difference between the in-vehicle temperature sensor signal and set temperature. A delay function is used to provide a gradual increase or decrease in blower motor speed under all conditions.

The blower motor speed control has internal temperature and surge protection. In the event of excessive blower motor supply voltage or current draw, or if the blower motor speed control temperature climbs considerably due to a failure event (such as a seized or partially-seized blower motor), the blower motor speed control will automatically shut down the blower motor. After shutdown, the blower motor speed control will attempt to restart every 120 seconds until the blower motor can be safely operated.

The blower motor speed control is located on the heater core and evaporator core housing near the blower motor.