last year my 2000 dodge durango slt was over heating so we couldnt find out what was making rango over heat so we changed the thermosat and the fluid and still over heated then we started playing with the relays and comes to be it was the relay we bought new relay and problem fixed now that summer's been here its starting to over heat again so i bought another relay and now i got the same problem car is overheating when a/c is on but when a/c is on it dont get cold at all . Would the freeon have anything to do with it? I need help im goen camping trip next week and i dont wanna burn on way up.

 

I would say you have 2 problems going on here.
1st You need to flush the system with a kit like this one.

use a flush like this

and buy a new thermostat with a bleed valve (the hole on the outer edge)


Flush it at least 2 times.... from start to end..

2nd you need to have the A/C evacuated and refilled

Other possibility is your clutch fan is not working.
Radiator is beyond flush with homemade kit and you should buy a new one or have it proffesionaly cleaned. (new one better option) this envolves removing the radiator and taking it to a radiator shop.
Keep in mind that the transmission is cooled threw the radiator as well, So every time you over heat it you over heat the transmission as well shortening the life of the fluid and the transmission far as that goes.


Welcome to the forum.....

 

lets start easy things first

is the CEL on? Does it come during start @5 Seconds?
this is a 5.2eng?
vehicle is STOCK?
does the radiator fan come on when A/C is selected?
when engine reaches temp does radiator fan come on?
check fuse #9 10amp in junction box
check fuse #2 30amp in PDC
Any problem with overheating when A/c off?
does the A/C compressor engage when A/C or defroster selected?

ps: I know its **** - but your vehicle does NOT use freon it uses r134A AKA SURVA

 

+1 on what schuster and kev said. Did you check if your efan was working? Kinda what happened to me. I had a leak in the a/c condenser and had it replaced. The mech told me my efan was busted so I replaced my efan and now no more overheating. HTH.

 

Take the truck to the car wash open the hood and spray out the condenser (radiator looking thing) with the compressed water spray then spray out backwards by the fan side. Get close enough that you don't bend the fins but hard enought to force everything out. Sometimes the fins get plugged with dirt and bugs causing the issue. Also check and make sure the electric fan is working.