Also with your temp control problem you mentioned, and fixed after shutting off truck sounds like a temperature blend door actuator concern. A lot of times when these sensors fail, they will send a bad position signal back to the control head. When the control head gets the bad signal is basically loses the position it thinks the sensor is in and shuts down the temp adjusment. Shutting off and restarting the truck basically is re-booting the control head (kind of like restarting a computer that locked up). This might be a secondary problem but I would suspect you have an actuator problem too.