I've owned this coach for 16 months and just saw something. The headlight switch pulls out one "click" while either in the parking lamp position or in the headlamp position. It has some kind of symbol on the switch, but I'm not fluent in symbolese. It appears that pulling the knob to the out position does nothing. I tried with the high beams, low beams, parking lamps and fog lamps. Couldn't see anything happen.
I'm guessing your Meridian has the smart wheel, since it has the 350 Cat engine, my model has the dumb wheel (and maybe the driver). There appear to several differences in the two.
Maybe on my model they chose to use a separate switch for the fog lamps and didn't use the function available in the headlamp switch.