Have same issue here.. The problem is BOB BOB is, of course a Burned Out Bulb.
So what to do about it..
Method 1: Tear hair out trying to find a new switch to replace it (possible but if you wish to go this route call the manufacturer of your Motor home or of the control panel)
Method 2:
Indicator lamp assemblyOn the back of the switch are 3 leads.. Two on one side and one (Ground usually) on the other.. Hook the black lead on one of the Indicator lamps to the Ground, hook the RED lead to one of the other terminals with the switch OFF, if it lights, try the other terminal
I just driled a small hole near the switch and installed it,, The ones I have were a buck a pop (When I bought 'em) at RS Electronics in Livonia, MI. (Not the ones shown in the link) and mount with "Speed nuts" (Spring steel things)
NOTE: this is not as bright as the OEM lamp in the switch, LED's last a LONG time, And I suggest you buy about a dozen of 'em give or take, They are very handy indicators.
NOTE: In another thread someone suggested a 12 volt outlet might be wired backward... Get two, one RED one Green, wire them back to back
That is the Green one the black lead connects to the ground (outer) pin on a 12 volt accessory plug and the red lead to the center pin, The RED one has the black connected to the center pin and Red to ground.
Plug it in . Green means Wired right, Red means Wired wrong BOTH means A/C outlet.