The automotive industry manufactures supply extensive information on the service and repair of their vehicles. You can purchase OEM service manuals that contain very detailed step by step instructions on repairs. This in necessary to allow independent service providers a chance to compete with the manufactures retail dealer service operations. To deny this detailed information creates unfair restraints on trade and will land a manufacture in an unfair competition and anti-trust action.
The same rules apply to RV manufacturers. Their failure to provide adequate service information, such as wiring schematics for solar pre-wire configurations, is risky business and at some point, if the trend continues, they'll be having pre-prosecution meetings with DOJ anti-trust lawyers. It also exposes them to product liability. The failure to give adequate information for service and repair is often the basis for product liability actions. It is quite foreseeable that a user will legitimately attempt repairs or installations of various systems such as a solar panel. If the manufactures fails to provide adequate information about which wires are which and a user makes a reasonable attempt to connect a solar system but ends up burning up the RV and some of the occupants, it is a virtual certainty that FR will be invited to the party in court and will probably lose.
Fires in occupied RV are terrifying. I know. I represented a defendant in an RV fire many years ago and no one in the camper escaped without serious 3 degree burns. When the jury looks at those horrible burn scars and hears each victim recount the terror of being trapped inside a burning RV, they are not inclined to give a manufacturer, who withheld information that could have prevented the fire, any break. It would not be hard to prove that their desire to withhold information was profit driven, as OG suggested in his post. If the plaintiffs proved it was more likely than not it was profit driven, it would probably result in a punitive damage award. Ford learned that lesson with their infamous Pinto many years ago.