Hi, my 2013 ACE 30.1 leveller system is probably different than yours but on my coach the actual leveller hydraulic motor is powered off the coach batteries via a 100 Amp cct breaker and the leveller control box/ driver panel seems to be powered from the chassis battery via ignition and accessory fuses located in the BCC. Not sure why your leveller system would say low voltage with engine running and be good when on shore or gen power. On my leveller wiring diagram at the hydraulic system area brown wire is ground but the white says chassis power; at the leveller controller box red says ignition (would be from chassis bat) and a second white says parking brake ground (different connector on the controller though).
Do any of your voltage readings change when on shore power.......especially the white one?
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