well as far as ur AC goes, the most common cause of poor cooling is a low system refrigerant charge so (you need to charge your coolant) which isn't too expensive....as far as your radio/lighter, sounds like a wire is lose i would take out the radio and double check all wiring, i think the lighter power wire is in the same vacinity or even connected to the radio 5v source, i maybe wrong but thats my 2 cents