If your chassis ( Freightliner ? ) is equipped with daytime running lights ; poor ground of the headlights could result in all the coach lights lighting up as the power cross feeds through bulbs and wires looking to ground.
Have you called Freightliner about wiring info ?
Have your serial number handy and call 1-800-385-4357 ask for schematics and diagrams .
The problem is that Freightliner wiring ends at the frame rail and then Winnebago takes over for the front cap and all the equipment they add.
But checking the light wiring ground wires in the front end should be your first step .