Are the slides hydraulic? When you hit the switch and the slide(s) start to move out and then click and stop, if you wait a few seconds and hit the switch again, do the slide(s) start to move again? If so, it is most likely the infamous auto reset circuit breaker problem. The click is the breaker opening. You may hear another click shortly afterward of the breaker closing, at which time the slides should work again. A common problem, and a cheap fix. The breakers sell for less than $10 at RV stores and auto parts stores.
Look for something
like this near your hydraulic pump, assuming your slides are hydraulic. Amp rating should be printed on the side.