On either the automatic A/C system or the manual A/C system the problem could be the climate control unit. However on the Automatic A/C system the mode control unit could be at fault. Also compare your type of A/C unit to the Heater wiring diagram I have attached and see which has the most in common with your system. This will help you find components that are part of both systems and therefore give you a better idea of which component could be at fault. You should also go to Advance Auto or Auto Zone and have your trouble codes pulled. They will do this for free and it will probably give you some more information on what is wrong with the system.
Images (click to enlarge)
Tuesday, August 13th, 2013 AT 8:50 AM