A/c Not Turning On

[TheTrueMoron]

Sometimes when I start my truck, my A/C won't come on. I try turning all of the knobs and I try turning the A/C on and off, but nothing happens. There is no air flow coming out of the vents and there is no noise coming from the air system. My warranty is about to expire but the A/C never seems to have any problem when it is in the shop. Does anyone know any specific area/part that I should have the mechanics look at?

[ryank1]

Start by checking the blower motor relay and next the control head. After that check the blower motor resistor.

[ChevyTech007]

The connector at the blower resistor is probably melted. Replace both resistor and connector.