2002 GMC envoy AC help?

[blonde-chick-91]

I need help. I have a 2002 GMC Envoy. Every time you turn the car on the ac blows cool air, but then when you turn the knob to add the temp on the passenger side it doesnt change a thing. then when you turn the knob back to 60 degrees when the ac is supposed to blow, the heat goes on. at that point you cant make the ac work again untill you put the car in park and shut it off and on again. the knob for the driver side works perfect when trying to make either the ac or heat work. i have replaced the two sensors for both driver and passenger side but it did not do anything. anyone think they can help ? or if you need more info let me know.


http://i105.photobucket.com/albums/m217/Maryana2009/TempControlCutout.jpg

the link is to what the control thing looks like with the knobs for the driver and passenger side.