HI there people! My air conditioning is giving me a big head ache. When starting my car cold, I can turn the AC on and it works like a champ! But after 5- 10 minutes of driving, the AC blows warm air. I pop the hood and notice that the compressor clutch is no longer engaging. At idle my rpms shoot from 800-1500 constantly like (woom woom woom woom), only if the AC is turned on and the compressor is not engaging.

what could be the problem????????