Vince Horton, try replacing the thermostat with an OEM product--it may have stuck close. It's also common for the passages in the radiator to become blocked by phosphate scale (minerals). This requires replacing the radiator. Also, make sure the radiator fan works properly--if not, check all under hood fuses, fan relay, and Engine Coolant Temperature (ECT) Switch.

I have a 2005 dodge ram and I am having overheating problems! It never gets to the boiling point but about half way between the middle red line and the hot line... We replaced the thermostat what else should we try? The mechanic told me that its either the censor or the radiator itself

Replace the radiator, if you sense passages may be blocked at all. Refill with a 50/50 mixture of G-05 antifreeze and distilled water. Purge the system of all air.