Jeep Grand Cherokee Re-Circ Door Replacement Process
Note that the process for replacing the re-circ door is more involved than the blend doors. Jeep just didn't leave enough access room for this to be simple. You can easily check the re-circ door by fully opening the glove box and you can see/feel the re-circ door behind the grate in the upper right. FAQ #2 on the web site will give more information. It's common for the door to break off and fall down into the fan motor intake, blocking air flow. If changing the speed of the fan makes it run faster, but air flow doesn't change, this is the problem.