Whenever i turn the ac on about 20 minutes later it starts to overheat.The fan works and theres antifreeze

Your jeep has an electric fan which should come on whenever the AC is on or if the temp goes over the 1/2 way point. It is fed by a 20 amp fuse in the engine fuse box. If the fuse continuously blows, replace the fan

The cooling fan is made to come on when the engine reaches a certain temperature. To give a simple and general test - turn the AC on high - it your AC and fan are both working correctly the fan should come on almost immediately. If not within very few minutes like 5 or 8.
Also at operating temperature the fan will run as well. In the early morning before you start the car open the hood - fill the radiator while the engine is still cold. start the engine and wait about 10 minutes or so. The fan should come on before the engine over heats. This may take up to 20 minutes and the fan is designed to run after the car is shut off IF - the temperature is hot enough.

Hi, dwings.
With your description, there are a few things that you can check.
First, check your antifreeze fluid to make sure that there is enough. Turn on your car and let it run for about 15 minutes, and then check the overflow tank. There should be coolant inside. If there's not, go ahead and add some.
Also, check to make sure that the fans behind the radiator are working.
Lastly, you may have to take your car in to your local (and trusted!) car shop, and have them check your water pump to make sure that it's still functional.
Try these steps. If any of these solve your problem, great! If not, please come back and let us know and I or another expert will think up a few more solutions for you.
Thanks for asking!
~Q

I believe you have a head gasket or cylinder head problem (cracked head or blown head gasket).. If it is the gasket, the intake and cylinder head must be removed and a new gasket installed.. If it is the head itself, in addition to what have just said, you will have to have the head repaired or get a reconditoned or new one. This is a major repair.

Yes. On the driver's side of the engine, frame actually (straight under the battery). If you remove the upper and lower part of the air cleaner. You will see a small fan relay on the frame. It has two 8mm bolts holding it in place, and one plug. Unbolt the two small bolts, slide the red locking clip over (on the plug) then squeeze the plug and unplug it. If you remove the lower air filter housing and look in there with a flashlight. You should see it relatively easily.

Ok if you do not check the engine loses antifreeze works well when you start or turn on uneven, check if the fan is working you bien.Thanks

Not good. I saw nothing about the fan being checked?

no the computers only job is too turn on the fans. check for enough antifreeze check for leaks. these cars are known for leaks. if the water pump is broke internally it will overheat with in minutes, or if the thermostat is stuck it will overheat too.

Sounds like your fan is not working. Moving provides the airflow rgough the radiator needed for cooling.. Over 35 miles per hour, the fan looses its role in the cooling systemto the forced air caused by your speed. Have your fan function ck'd Good luck.

GET COOLING FANS CHECKED SOUNDS LIKE A DODGEY FAN OR FAN SWITCH