TRAVELING ON THE CROSSTOWN FREEWAY @ THE POSTED SPEED, I STARTED TO ENGAGE THE VEHICLE'S HEATER AND THE POWER CONTROL SWITCH STARTED TO MALFUNCTION. I TURNED THE POWER CONTROL KNOB CLOCKWISE AND NOTICED SLIPPAGE OF THE CONTROL KNOB. I NOTICED SMOKE COMING FROM THE WHOLE HEATER CONTROL ASSEMBLY AND THEN AN ARCH, THEN A SMALLFLAME. *TR