1996 GMA Sonoma: For the past few months, my air conditioner will not switch from the defroster (blowing out of the dash) and the floor vents to the vents that face the driver and passenger. I have no problem with the speed of the fan or turning it off and on. Does anyone know what would cause this? Is something sticking? Thank you for your prompt response as it is getting a little warm to run without the A/C. Thank you for your prompt response!
Find the black vacuum ball in the engine compartment. It has a plastic hose from the intake and quite often the hose will burn or come apart. I am sure it will fix the problem. I have fixed a ton of them. Good Luck