Hi JDS,
exactly the same behavior here. I`ve got an "Dethleffs" Camper, Split Charger for Engine and Leisure Batt., Leisure Batt is a Gel-Batt, starts loading at 14.2 V IoUo Line; Engine Batt is a standard 80Ah Wet Battery (approx 6 months old), loads with approx 2A straight `til full. At the first rising of the problem, i`ve tried to start the engine with lights and radio and vent and so on - no starting problem... starter turned as usual... Cab Battery either is ok, no Voltage Problem shows up... and both circuits are separated when the charger is "offhook"... errm gets no 230V ... ****.. i thought that there must be a cable providing power to the Clock electronics while the engine is off, and maybe this one is down.. or a fuse is broken.. but i can not find something in the "fine" manual.. tsssssss.. such a lot of fuses, but noone seems to be responsible...
Any other idea ??
L8er, best wishes, Manfred