You may have a pre-Schwintek slide system, so I am not sure how much I can help.
With the Schwintek system, there is a control panel somewhere that provides error codes if the system isn't working.
If your system is pre-Schwintek, I would still expect some kind of control panel.
The photo is for a Schwintek control panel, but you may have something similar.
And it could be located anywhere. The panel for my Schwintek system is located inside one of the outside storage bins, so open each of those and look inside.
And if you have a Schwintek system, the slide motors are built into the slide itself, hidden from view.
You can easily tell if you have a Schwintek system by looking at the slide out (of course, it must be out to do so), but perhaps you can go by memory. There should be an aluminum rack, top and bottom of each side of the slide out.
They look like this:
The main fuse for my system is located in the fuse panel, labeled Slide MTR PWR.
Again, this might not be the same for your coach, although I mention it as it might be similar.