I have a 2004 gmc sierra so it should be the same,and i found three actuators on mine.One is no the hump by the passsenger side by the Bose speaker. This one controls the driver side temperature.The other is by the duct on the driver side it by the pedals. This controls for the air to go from your face to ground.the last one is in the center of the console.You have to take the whole dash off for that one.This one controls the passenger side.
The outside temperature sensor on the 2005 Chevrolet Silverado pickup is located in the top of the dash next to the windshield. Look for an area that looks like a speaker but is shaped like a triangle.
What temp. thermostat did you put in? Try a higher temp. one. or check to see if heater core is clogged
thermostat
On driver side of block by the bolt in exhaust manifold closest to front of vehicle
There is a temp blend door controlled by the temp control switch. The temp blend door is run by an actuator. If this actuator needs replacement it requires removal of the dash assembly (big job).
It is screewed into the drivers side head all the way up front beside the FIRST spark plug.
210
Behind the glove box
the intake air temp sensor for an 07 Silverado is built into the MAF sensor. The MAF is located on the air intake hose.
The temperature door actuator controls the opening to the heater core. The heater core door regulates the desired temperature in the passenger cabin.
The temp blend door actuator would be found behind the dash assembly mounted to the HVAC box. Unfortunately the dash needs to be removed to gain access to the actuator.
The temp blend door actuator has failed.