When i am siting for about 20 min with air on, it starts to run hot. Right on the top of the bar to where anymore would be overheating. (Noticed when i turned on the lights it went up faster) Could this just be a typical thermostat?

 

Buy yourself a simple test tool from the auto store. Checks the boiling point of your coolant system. Thermostat would be the second thing I check. Engine oil level? Corrosion or restriction in the coolant system. Things like that.

 

Your fan clutch is bad.
Check the tech section for a cost effective replacement option.

 

Spike is, as always, right on the spot. And do not trust that guage!!! If you use a scanner, you will find the coolant temp is way above 230 at that point on the useless meter. The first 1/3 of the scale is "normal", the middle is "NOT AGAIN", and that last 1/3 is "OPEN WALLET". I did not believe this either, until I bought a scanner that could read it. And while you are at it, clean out any trash between the condenser and the main radiator.

 

And the fan clutch is a piece of cake to replace. Picture 1 - use a wrench or channel lock pliers on the fan shaft nut and pop sharply toward the coolant tank (right side of truck). Assembly will spin off after breaking loose. Picture 2 - The Imperial fun clutch for a Chevy (see sticky) 4.3 fits our fan, with just a slight drill out of our holes. I could not find the correct length bolts, so I have cheezy spacers. Picture 3 - the radiator side of the fan clutch sports a thermal spring and smooth surface. Per the factory, the fan begins to engage when the air temperature reaches 170 degrees, which is about 200 degrees for the coolant.

 

Thank you all ...you dont know how much i appriciate this !!! I will start on the fan clutch !!!