1982 Ford Coachman
I suggest that you ask the owner to demonstrate that everything in the RV is working. That means that they should connect it to power and to water and turn on the refrigerator and make some ice, turn on the water heater so that it has hot water when you arrive, and demonstrate the use of all plumbing and the toilet. By having the water on, you can check for signs of a leak in the water system. I would also make sure that there is water in the tank. Turn off the city water supply, then run some water using the water pump. Listen to it operate, and then turn it off and listen again to see if it stays off. It the pump runs more than once an hour or so, that also means that the water system leaks somewhere. Ask them to turn on the air conditioner and make sure that the air out of it is at least 18 degrees cooler than the air going into it. Once you know that cool air is available, turn off the air conditioner and turn on the furnace. Allow it to run for at least ten minuter and make sure that it blows very warm air. Check the DOT code on each tire and the last digits of that number are the date the tire was made. It will show the week, and year. (319 = 31st week of 1999) or (2403 = 24th week of 2003). If the tires are six years or older they should be replaced before any long trips. Look for any signs of leaks, such as stains or delaminated wood inside. Leaks that have not been repaired can lead to major structural problems. That should get you started.