ok, so i was changin my dead battery and my lil brother was helpin, and he put it in backwards. the ground to the postive on battery and battery ground to pos on car. so like he just touched it for a sec and the horn started beepin andwhatever. well now the radio/clock/cdplayer/lights on temperature controls dont work. checked fuse, its fine. the defrester and vent and everything work. just radio/cd/clock and they're respective lights dont.i just need to know what would have popped cause a backward battery. thanks for your help.