I have a problem I was driving down the road when a bunch of smoke started coming out of the bottom of the dash and the heater stopped working after the smoke cleared I checked and changed the heater and a/c condenser fuses but the heater still doesn't work.
It stayed like that for a while I've checked everything and still can't figure it out just today I was in my car and I unlocked the doors and the heater kicked on for the split second that it unlocked the doors so every time you unlock the doors the heater kicks on this is on a '93 civic ex thanks in advance.

 

sounds like an electrical problem. get under there and check for burnt wires