A Common fault with the Jeep Grand Cherokee is the need to replace the Air Conditioning condenser. This is often needed even if the air conditioning condenser is not faulty.
The reason for the need to replace the condenser is actually caused by the failure of the transmission cooler. In all their wisdom the good people at Jeep decided to combine the transmission cooler and the air conditioning condenser in the same unit.
If you look at the image accompanying this article you can see the mild difference in colour roughly halfway down the cooler. This shows the two different components in the one unit.
The transmission cooler is common for leaking and when it does it will require the air condition system to have the gas lawfully removed before doing the repair. Then the Front bar needs to be removed and the condenser replaced.
This repair is a time heavy repair and will cost a significant amount in labour.
Additionally the transmission cooler lines are a bit tricky to remove. You need to push back the plastic ring and using a small pick remove the retaining E Clip. If a heavy hand is used the cooler line can be damaged too.