Automotive AC – Control Heads

The control panel is the device that allows the front-seat occupants to select the desired operation of the HVAC system. The control head has settings for the mode, the temperature, the air source, and the blower speeds. The era of the vehicle will determine what kind of service can be performed on the control head.

Older vehicles had some serviceable parts on the control head, such as the blower switch or the vacuum switching valve. However, more recent vehicles have control heads that are fairly electronic in nature and will likely need to be replaced as an assembly if problems occur. The main point to check on a control head that does not work is to make sure it has power and ground supplied to it.

Circuit breakers are used to protect circuits and are located in the fuse block or in the power distribution center. The circuit breaker on the left is a manually resetting style and the one on the right is an automatically resetting

Vehicles with automatic temperature control have very advanced control heads, and it is often possible to use the control head to retrieve diagnostic trouble codes from the control head by pressing a series of buttons. This is a handy diagnostic strategy that will assist in finding problems with these advanced systems.

Another handy routine that is often available on these advanced systems is calibrating the duct door actuators. This is accomplished by depressing a series of buttons on the HVAC control head. These routines are available on most reliable service information databases.

The HVAC control head on older vehicles is fairly reliable and very simple in design. These control heads often have a vacuum switching valve to control the vacuum-operated duct door actuators. The blower motor control switch can sometimes be a serviceable component on this era of control

Leave a Reply

Your email address will not be published. Required fields are marked *