So I got my car back from the body shop, and suddenly my A/C doesn't work. The heat still works. Normally when you turn it to the air you can hear everything come on. I am getting nothing but ambient air. I checked the fuses, and all seem to be ok. Does anyone know where the schrader valves are for it, and is it 134a refrigerant. Any other ideas would be helpful. It is a 1998.