Have you tried disconnecting from the city water to see if the pump will run? Your pump likely won't run while on city water because the pump will only run when there is a demand or low water pressure, and while on city water the pump does not have to supply either.
Also perhaps the light in the switch has burned out so you
DO have power to the pump, but there isn't a demand for water (because you are on city water) so the pump won't run.
Failing all that making the pump run I would next check the fuse and/or put a test light on the + wire at the pump to see if there is power to the pump and go from there.
Hope this helps you out.

Jimmy