Smoke comes out of the heater controls of my daughters 91 camaro when she has anything on except for the defroster. Its fine when the defroster is on but as soon as she moves it to heat, vent or anywhere but defrost smoke starts coming through the controls. Any suggestions on what is wrong with it? Thanks, Dave

Is it smoke or steam. Maybe heater core , just a guess.

She says it is smoke.

Is the floor wet might be heater core i had to change the core in my iroc,or does it smell like wireing burning the switch or pigtail may be overheating and be melting