I read some previous messages about a 99 DeVille that had the reverse problem. Is this just the oposite sensor that is out? Is it easy to get at?
When you get behind the glove box what does the accuator sensor look like?

Well I figured out the problem. It was the valve that controls the heat to the drivers side. That valve is located on the passengers side just under the access cover near the floor.

Well I figured out the problem. It was the valve that controls the heat to the drivers side. That valve is located on the passengers side just under the access cover near the floor. DWADE WHAT DOES THE VALVE LOOK LIKE? THANKS

DWADE WHAT DOES THE VALVE LOOK LIKE? THANKS
It's black and is screwed down with 5.5 mm gold screws-Sort of like a black square-With a rod connected to it--