Another thing that controls the temperature is the sensor above the drivers head in the headliner, it has a little fan inside and a they get clogged up or just don't properly after some years, there is also one in the back above the rear passenger, they run about $25 each online, easy to replace just pull the headliner down and unplug and replace. To check the if they are working properly you really need a tech2 but for the price to just replace them it's not that much, it may or may not resolve you issue but is something else to consider.
