Check for melting.
The link below has the same article in post #10 without having to download anything.
""to remove heater control box for inspection""""
Remove the defrost vent cover , pull up on the far side not the middle. pops right off.
Remove the ashtray. Open it and push down on the tab on the inside and slide out.
Remove the screw behind the ashtray.
At the top of the center bezel where you removed the defrost vent cover,,,remove the 2 screws that hold on the bezel. Pull the whole center bezel off..pull right off.
The heater/ac controls will have a few screws holding it on...take them off.
Poof your done. and can inspect the controls.
READ through this WHOLE thread. And the links in post #10.
If you have any more questions let us know.