So I connected an alligator jumper from the ATS Neutral terminal (normal generator in) to the campers copper ground wire (both located inside the uber narrow basement…) and the relay WORKED !!…So this points to a poor neutral to ground connection somewhere at the main or inverter’s sub-panel (the originating end of the newly installed ‘inverter to ATS’ wire run…)….:)
I also discovered a ‘tingling sensation’ when touching the camper’s frame…Tingling sensation went away once I connected the aforementioned jumper…
3 tons