Boiling battery with sulfur smell means severe overcharging or internal short. Disconnect immediately - hydrogen gas is explosive. Battery must be replaced. Check converter/charger output voltage before installing new battery to prevent recurrence.
ME2012 showing 50A fault, self-test failure, and breaker trips indicates internal inverter failure or ground fault. Disconnect inverter to test shore power separately. Check all connections. Likely needs professional repair or replacement.
To fix parasitic power draw through your 2006 Damon Challenger's instrument cluster, use a multimeter to isolate the circuit, check common culprits like clock memory and sensor wiring, and find alternative wiring diagrams through Freightliner chassis documentation or aftermarket sources.
Check internal DC fuse first - common failure point. Located inside inverter behind front panel. Also verify battery voltage at inverter terminals and check MATE controller cable. No display with fan running often indicates blown DC fuse or control board failure.