You clearly want a fuse or circuit braker installed before the monitor and close to the battery positive. Any electrical device in the trailer should be fused. This is especialy true in an all metal chassis. If you feed wire to any electrical devise ever cuts through the insulation and touches the framework of the trailer you got a problem. Fire is not a major risk but attemping to rewire through an Airstream chassis is a problem.
WBCCI 12156 AIR 3144 WACHUNG TAC NJ6
2004 Excursion 4x4
1991 34 ft. Excella +220,000 miles, new laminated flooring, new upholstery, new 3200 lbs axles