My 02 Explorer has a very annoying clicking sound comming from the left rear of the vehicle, it only happens sometimes though, I think it has something to do with the rear A/C. Any Suggesions??

There is an actuator in there that may be failing. Remove the panel and look for it.

What exactly am I looking for?, any pictures?

Here ya go. Directions and drawings from the manual. Hope it helps.

Auxiliary Temperature Blend Door Actuator — Air Distribution
Removal and Installation

Remove the LH quarter trim panel.
Disconnect the wiring harness.
Disconnect the electrical connectors.
Detach the electrical connnector pin-type retainer.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac.gif

Disconnect the vertical air duct from the auxiliary climate control housing.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac1.gif

Remove the bolt.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac2.gif

Remove the bolt.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac3.gif

Remove the nut and position the auxiliary climate control housing away from the quarter panel.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac4.gif

Remove the air distribution blend door actuator.
Disconnect the electrical connector.
Remove the screws.
Remove the air distribution blend door actuator.
http://i153.photobucket.com/albums/s214/way2old1/rearexpac5.gif

To install, reverse the removal procedure.

Way2Old, is there a blower motor in the rear of the '02 Explorer as well, near the actuator? If there is, I'm wondering if the noise could be something in the blower motor squirrel cage.

-Rod

There is a blower motor there also. When the trim panel is removed, the poster can determine exactly where the clicking is coming from. The most common failure is the plastic gear inside the actuator not allowing the motor to shut off. Just tries to keep moving the lever.

Thanks Guys I will be opening and investigating ASAP, I will let you know how it turns out.