I have an 05 HR Endeavor, and slideouts stopped working last fall (no movement at all on all slides). I found a fuse on a circuit board on the back wall of the battery compartment, under a plastic cover that was the culprit. There were 2 small 12V fuses on the board, if I remember correctly, one was a small 3a, the other a silver looking 15a (I think). The 15a was bad. Good luck.
Edit: Looked in my OM and guess it is a relay, not a circuit board, but you might check that fuse if yours is similar
05 HR Endeavor 40PDQ