I need help finding a gremlins the A/C system.After a little while of running the GTA's heater,There is a burning smell and a little smoke that come from the defrost vents.it usually happens when i turn off the heater.What could it be !?! I want to find the problem before Fall/Winter comes in, or before the dash goes up in flames

 

There might be some debris stuck in the resistor coils in the heater box. It's the ones that allows for all the less-than-full-speed operations of the fan. They are located where you see some wires plugged into a (removable) panel on the box.

 

Where is it located? Under the passenger side,or on top of the heater box? when i get home on the 29th this month,i'll be replacing the heater core...What fun....

 

On a Camaro it is located right next to the blower motor in the engine compartment. The plug will have about 4 wires going into it and there are two mounting screws that hold the coil in the blower box. When you take out the screws you will see the coils when you pull it out. You don't even have to unplug the connector on most GM cars if all you want to do is check the coils. Mine have burned out a couple of times....