First things first, as someone else said, locate the slide controller and see if it is flashing a code. The code will be the number of reds flashes between green flashes. If the controller is flashing a code the slide may not sync no matter how many times you try.
Also, if the coach has an overhead bunk the controller for the bunk may be the same as the controller for the slide. If they are the same you can swap them to see if the slide begins to work.
The slide controller looks like this
Thor Forums
