Hello best and brightest of Cartalk,
I have a 2003 Jeep Grand Cherokee with about 240000 miles on the clock. Words cannot describe how impressed I am by this car. However, yesterday I noticed that the selector switch where one chooses to direct the air output has failed me. It seems to be stuck in the windshield defrost setting, unable to redirect the airflow to anywhere else. I am however still able to control the temperature as well as A/C settings. The switch felt strangely ‘limp’ almost as though it is no longer connected to whatever engineering or witchcraft it is attached to behind the control panel. What are your thoughts on this? Could it be as simple as some mechanical linkage that has snapped off?
Just to recap: blower motor, heat and A/C are not affected by this. Thank you for your answers and advice.
If it has manual A/C control (three large knobs) check the vacuum supply hose from the intake manifold to the firewall.
If it has automatic temperature control it uses servo motors, you will have to perform a diagnostic test.
If it is the manual control not auto temp then the switch is a vacuum switch. There is a goofy connector with several vacuum hoses attached to it. But since you say the switch feels different, I think you will need to get the control panel.