12 volt system not working

[Golferdave]

Hi All:
The 12 volt system in my 2013 Montana RE 3800 does not work when not plugged in to shore power. I have a RVI Progressive PD 4590 Power control centre. I have 2 new 6v deep cycle batteries ( thinking this was my problem ) ( Delco 6v deep cycle 845A batteries ). I believe I have checked breakers and fuses. The Power Control PD 4590 was replaced Feb 2016 by a certified RV tech in Penticton, BC.
I have nearly always operated my slides and leveling system when attached to shore power. If I unplug from shore power all I get is a "click" when trying to operate leveling system.
I am stuck here in Oliver, BC. Trying to get across the border and to our winter haunts in Apache Junction, AZ. It is getting COLD here.
I have spent some time at the Montana Owners Club web site but am confused. Thank you for any help.
Special hello to H John Kohl. Thank you for your kindness.
Golfer Dave