Carol.

we had the same problem last year. we were in the Upper Penisula of Michigan, getting ready to leave our sight and make our 800 mile trip home. Running lights did not work. Brake and turn signals did. Checked fuses and our Tacoma and found blown fuse for our running lights on the truck. Replaced it and then plugged the trailer back in. Everything worked for a minute or two and bam, fuse blew again. Afetr a couple of fuse replacements in a driving rain, I said the heck with it and decided to wait until the rain stopped and then started heading home. Only drove in the daylight. When we finally arrived at home, I started checking the electrical system. I found the culprit. It was at the lead cable that plugs into my truck. Where the cable goes under the trailer tongue area, had a worn spot. When it would rain, current would jump to ground resulting in a blown fuse. How do I know this was the problem? First, I dried the cable very good and then put a new fuse in. I moved the cable all kinds of ways while dry. No problem. Next, I hosed down the same area, moved the cable and fuse blew. I repaired the cable then wrapped it with flexable,black conduit. No proble since. By the way, the area that had rubbed. I was rubbed flat and you could not see the wiring. Current just need a place to ground and followed the least path of resistance.:)

There is a common problem and not just HI-LO's the terminal ends on the wires are crimped on, they tend to corrode inside the crimp and lose contact. The worst place in a HI-LO is in the battery compartment, due in part to the battery gases. Auto manufactures use sealed water tight connections along with grease inside the connection to prevent this. Trailer manufactures go cheap due to their small production compared to autos.
I had numerous problems with our 95T, untill I soldered ever terminal in the battery box and coated everyone with no corrode grease. Never had a problem after. When we bought our 2209 it was a year and a half old from date of manufacture, I checked the terminals and some were starting to corrode, so I did the same to it as the 95.