gfs 1943 is the correct answer for the rocker switch on the right of the guages.
dash radio likely has a switch also. Should be on right side of gauges down the line with the others. It will say "Radio power" -- AUX on one side -- MAIN on the other. Probably under the battery disconnect.
The solar panel, you may have to get up on the roof and gather numbers. I bet Winnebago has one in their "extremely huge" warehouse.
Dont know about the spotlight on Winnies. I have seen a very few "anythings" with them, however there is usually a small joystick on the drivers armrest (from the few Ive seen) that operates the spotlight.