two guesses. does your battery light come on too? if so...its your alternator. change that bad boy before it leaves you stranded.
if not...your ebrake might be caught up. i'd let mine down but one side stuck...so, everytime my dumbass forgot about it and pulled it up anyway, i'd have to go back to the brake with pliers and yank it of. eventually it got so bad, the brakes would smoke SO bad. stanky! and it got stuck real bad. after about 20mins of yanking, it finally popped. then i was good. hasn't f**d up yet.