Patti, if you have not already arranged for it to be done, call the person who owns it and ask him to fire up the fridge right than and there so it will have time to get cold before you get there. Same on the
water heater. Then if they are not functioning, ask why (probably you won't really know), and consider carefully why. Same on the fridge. These are big  ticket items, but not the only ones.

Does the univolt/converter work? Is there a battery in the trailer and is it charged? If yes, pull the electric supply cord, and see if your 12 volt lights go out. Then listen for the hum from the univolt when
you plug back in. If it is real loud that might spell trouble.

Check of course for decaying or rotten wood, around and under water connected items (kitchen sink, bathroom lavatory, commode) checking also the floor in front of the fridge. Check around the perimeter
of the walls/floor, and especially at the entrance door area.

And on and on! There are the obvious items such as tires. Find out when the wheel bearings were last repacked and what was the condition of the brakes. Before you sign any papers, take it for a test ride just like you would for a car. Do the brakes work well? Are the riding (clearance) lights on when your tow car lights are on; do the turn signals and stop lights work. Look at the body just above the two main chassis frames at the rear. Does the body show a crunched area just above those frame members. Or is there a wide gap across the rear, usually on one side, at the bottom of the body where it joins the chassis. ETC ETC

But don't be apprehensive. You will have to trust the seller to some extent, and if he/she is an old=time, long-time 'Streamer there is better likelihood that you will get the truth. Older trailers are not perfect --
for that matter, neither are the new ones! If it feels right, and you want it, knowing that what you pay for it is not your last cash outlay, go for it. Then enjoy fixing the things you will discover need R&R.

You'll end up having a lot of fun, and you will learn about Airstreaming. About the only way you really, deeply learn.

Donald WBCCI #2875
kribbsdh@webtv.net