An engineer friend got a new pickup with an inverter. And he has a boat with an inverter. His pickup inverter is advertised as grounded. The Fluke shows no ground on the pickup, But 58V between neutral and ground terminal and 58V between hot and ground terminal. With no load. His boat shows everything great just as it should be. No matter where he is ,Shore or at sea. I told him to drive a ground rod at the pickup, "Half way joking" Any danger at pickup with no ground. I feel there is. But I look at how many are out there and haven't heard of any problems.