I am the new owner of a 1994 Eurovan Westfalia (short wheelbase). Just installed a fresh Optima deep cycle auxiliary battery. Sink pump and interior lights work fine, but I can't seem to be able to turn on the fridge with any reliability. When I press the power and fridge buttons simultaneously often what happens is the display shows "-- C" and the fridge won't turn on. Occasionally after some driving (say, 30 mins) I'll repeat the same sequence and there will be a number (ie. temperature) displayed (eg. "8 C") and the fridge will turn on and work fine for the rest of the drive. Any suggestions/advice would be appreciated trouble-shooting.