When I bought this 2018 Forest River Salem it was in pretty good working order, but like most things it started to have little things go wrong. On one trip I was taking the trailer off the truck with the powered jack. It lifted three quarters of the way off the truck then quit. Luckily I found the manual crank. Thanks to my good friend Bill he was able to assist with checking the circuits with a meter. They all seemed fine.
After searching for the culprit a little longer it occured to us to check the water level in the batteries. The water level was way low. We filled them up and put the trickle charger on them for the night. That did seem to help.
However, over time it seems they still didn't hold a charge very long without being recharged manually with the charger. At this point I believe the batteries are dead and need to be replaced.
Moral of the story is - Even the batteries need to have regular checks done to make sure the water levels are full and there is not corrosion on the connectors.