It could be as simple as someone doing a sloppy repair, perhaps replacing a cable that was pulled out of the connector and not bothering to remove the connector from the solenoid. In that I can see a cable lurking behind your hand and can guess that it was previously connected to the solenoid, I'm thinking that orphaned connector has nothing to do with your current problem. It is unlikely that there needs to be two cables attached to that post on the solenoid.
'04 National TropiCal T350
Behind the coach: