Thanks for the suggestions. We're in the middle part of the story now and my father-in-law is waiting for a tech to come to the campground to check it out (hopefully in the next day or so), so we'll see what happens after the tech takes a look at it.
I feel so bad for him. He's 80 years old but has never let age (or mechanical problems!) keep him from joining us on trips. This time, though, he seemed pretty defeated and I'm sure it's really bugging him. The first part of the story is that on the way to the campground we pulled over on an exit to grab some sandwiches, which is where he discovered a fuel line had wiggled off. Thank goodness we "just happened" to stop before it became a much bigger issue. He tried calling Roadside Assistance but they couldn't line up a mobile tech or a tow on the weekend so they stayed in their motorhome on the exit ramp overnight, about an hour away from the campground. Like I said in the original post, he can fix anything, so by morning he had done enough tinkering to get it running again and they joined us in the campground.
So with the slide still stuck in the extended position, yesterday ended with them coming back home with us in our tow vehicle and another family member meeting them at our home to get them the rest of the wait to their home, and with a call in to a tech in the area where the camper is at to take it from there. When they get the all-clear they'll make the 400-mile journey to retrieve their motorhome.
There are many family conversations of "updated smaller motorhome" starting up, I have a feeling this story has a ways to go before the final chapter is written. :-|
