Luckeduck, If you flip the switch on next to the gauge you should hear the pump running. If not then you do not have power to the pump or gauge. It is possible that your switch is bad if like you said it is hard to toggle between on and off.
Like I posted most have an inside switch that has a time out feature. I would think they do this mainly for safety, so the fuel pump shuts off if you forget to flip the outside switch off. The other reason is security. Most fuel stations are in a locked compartment that would be easy to break into and steal the fuel. By having the main switch inside the rv adds another level of security.
Yea, be careful but if you turn the propane off at the tanks you should be safe.
If it's water no problem, at least you will know what it is.