How do i repair my heater? worked fine til someone stole my stereo.?

My a/c and heater was fine until someone stole my stereo. now i cant use the heat to defrost my window and driving at night sucks. i plugged the switch back to the correct spot so that i hear a click as i turn int left to right to control temperature. other than that i have no idea. its a 97 civic honda. also i can't listen to radio on my new stereo. why? i plugged the antennae in right so it should be but its not.