Ford: temp.gauge reading hot, radiator cap, bullitins

Question
I have a 2002 sport trac. Temp gauge reads hot and the heat inside truck is barely warm. Had the thermostat changed but no change. Also the reserve for radiator was empty so I filled it. After running truck for a good while the radiator cap is still cold... You can remove cap after running for 50 miles. Need your help...what to try next?

Answer
belive it or not the cooling systems in these newer vehicles are verry efficent... the first thing that I would try to make sure all of the air is out of the cooling system... after that let it run with the air conditioning off until the electric fan turns on... (To make sure it is working properly) I'll go online and see if there are any bullitins for it...