My air compressor is not coming on, I have checked the fuse and it was fine and tried another relay and that was not it. Does anybody have any idea what may be wrong a/c had been working great right up unto the point it quit???

 

Go to the HVAC section and see the FAQs.

 

it's probably low on coolant. there's a low pressure switch that prevents damage to the a/c compressor once the level of coolant gets below a certain level.

like the poster above me, go read the FAQ's on the HVAC.