Not sure on the Salem, but we have discovered on travel trailers that many times the Awning, slides, and stabilizers, and tongue jack are wired in a way that they are ahead of a battery disconnect. If the battery is decharged, or had a battery shutoff, then these items will not function......... irregardless of all the other 120 volt things or 12 volt items that run off the converter.
I would advise if you can trace the wiring from the battery, and see if you have a disconnect (or have you turned an OE disconnect on and forgot about it) that's not letting the converter recharge the battery.
Also you may have a resettable fuse that's tripped. Here is another forum with pics of it. You will need to press the little black button on the side of it. It's usually very near the battery itself on the frame railing.
Battery not holding charge in new 2016TT
Hope this helps and you have a simple problem.