If you have the integrated controller and towing mirrors you have the towing package. Check the 40 amp fuse in the engine compartment to see if it's blowen. The inside of the lid on the fuse box will tell you which one is the trailer fuse. If its ok ...
If it does not have the towing package on the Ram you will have to add the 40 amp fuse. It will be in a black fuse box in the engine compartment and will be clearly marked.
The only way to tell if the curcuit board is bad is to replace it, so you might want to take it to a RV repair place and let them do it. It cost me 350 bucks cdn to have mine fixed.
I had the exact same thing happen to me last year and it turned out to be a stuck relay on the furnace board. I could bang on the furance to get it to start some times but after awhile even that did'nt work. They had to change out the whole board to ...