The control unit on my Autocruise Starburst, even when switched off, still displays info to scroll through, including voltage at cab and hab batteries. Today the leisure battery was reading 12.7 volts - but when I switched on the control unit, it went down immediately to 12.3 volts. Any idea why? There was nothing switched on, so as far as I can see the only additional current drain was the red LED on the control unit to show I'd switched it on!