Don, I had something similar happening on our rig, on the bedroom slide. While at Paul Cross's I mentioned the popping, he said to look closely at the cable connections, they sometimes turn or "twist" and the popping you're hearing "may" be the two cable connectors coming in contact with each other as they pass by each other. Paul told me to try twisting the cables slightly so the connectors don't touch each other as they pass. That was indeed our problem! Easy peasy! NO more popping
Paul told me not to let that go on for too long or "you WILL be replacing one or two cables"!
Good luck, let us know what you find.
Dan