Hi,
It's possible you have one slideout controller module for both slides. That's the way our Georgie Boy is wired.
The click you hear, is that a light, faint click? If so, that could be a relay in the control board energizing. Use that to help track down the location of the controller. Have someone press the button while the person with the best hearing tracks down the location of the click.
Once you find the controller, make sure all of the wire connections to it, especially ground, are clean and tight. Ours left the factory with a loose ground wire that didn't really manifest itself until about the third year. By the time it started preventing the slides from operating properly, that wire had charred up the wire about 6 inches up from it's connection point. The loose connection causes heat build up.
If you can start your rig and operate the slides, see if that helps. The extra voltage on the battery can make a big difference. Our slides will not extend if the engine is running, but they will retract with the engine running.
But there are numerous variations on this theme.
Good Luck,
~Rick
2005 Georgie Boy Cruise Master 3625 DS on a Workhorse W-22
Rick, Gail, 1 girl (27-Angel since 2008), 1 girl (22), 2 boys (23 & 20).
2001 Honda Odyssey, Demco Aluminator tow bar & tow plate, SMI Silent Partner brake controller.