You may want to try the forum for U-Haul
campers to get more specific information. The site is www.uhaulcamper.com/forum
. There aren't a lot of U-Haul's out there, but welcome to the group! We have a 16' VT that we have been using for about 2 years (1986 model). From what I know, the windows
may not be available any longer, but you can certainly get a window for another camper that may require a bit of fiberglass cutting to fit. Other folks have used a single sheet of plexiglass or similar and fabricated the trim/housing. The AC may just be shot, or it could be a wiring problem. I assume you're trying to run it off 120 v.? The circuit breakers may be tripped or the wiring may have come loose. We have a Coleman Polar Cub on our trailer and it works great. Dometic also has the Duo-Therm that would fit.
This would be a labor of love, but well worth the time and money. The 13' CT is a great little trailer and tows very easily. The price sounds good, too, unless the frame is shot or there are major holes in the fiberglass. Many CTs go for $3,000 or more.
(P.S. - Search through the U-Haul
site above to find the answers to many of your questions. It may take a day or so to get a live response, but there are several dedicated U-Haul
owners who are very eager to share their knowledge.)