Welcome to this forum.
I was thinking if monitor isn't connected to hay baler wiring harness that monitor wouldn't function correctly so your thoughts on water intrusion might be correct. I'm guessing that from some of your statements you have monitor is set in netwrap mode. If my guess is correct have you attempted to change monitor to twine wrap mode? Does your 466 have regular or mega-wide pickup? Yrs ago I purchased a new 466 with MWPU. I like my 467's MWPU balers much better
I was thinking if monitor isn't connected to hay baler wiring harness that monitor wouldn't function correctly so your thoughts on water intrusion might be correct. I'm guessing that from some of your statements you have monitor is set in netwrap mode. If my guess is correct have you attempted to change monitor to twine wrap mode? Does your 466 have regular or mega-wide pickup? Yrs ago I purchased a new 466 with MWPU. I like my 467's MWPU balers much better