As Ed mentions, there have been many postings with your symptoms that were the result of the control panel (at dash) having a loose connection or strained wire bundle. I loosened my bundle by moving the strap holding it a bit. The problems can be intermittant or unchanging, depending on the looseness.
Take apart the two passenger side panels below the dash so you can see the drawer and related wiring as you move it in and out. You may just find a loose or pinched wire. From the sounds of it, the problem is likely a bad connection, likely there.
When you checked the fuses, did you check all the ones indicated in the HWH Owner's Manual. There are many fuses and in different locations:
Here's for three slides. http://www.hwh.com/ml13997.pdf
Here's for two slides. http://www.hwh.com/ml19754.pdf
(ignore the engine access door)
My control unit was center coach, under water tank, in first bay, behind a carpeted panel, next to the main tank drain valve.
Good luck, as frustrating as it is, it will be something insultingly simple.