We were camping this past week in Lancaster County Pa and had a very bad storm roll through on Tuesday and had a lightning strike about 15 ft in front of our motorhome. It blew off the cover from the ...
"One of the simplest and yet most effective means of diverting lightning energy is to put a loop or two in all leads entering or leaving the equipment building". (RV = 'building')
and......
"All that said, the easiest way to protect an RV is to simply unplug it when a storm approaches".
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Lots of other sources - here's one brief & to the point -