You can replace the switch for the pump. Obviously power is getting to it or the pump wouldn't come on. It's just not lighting up
You can pull the monitor panel & check connections there also, but it too probably needs replacing. Having said that, the monitor is not reliable anyhow. It can only read what the sensors say for the tanks & they may not be working any longer. I believe most of us don't rely upon the panel to be accurate, especially for the battery. DON'T rely on the monitor for the battery. Best to get a hand held multimeter to check voltage, or install a meter inside the coach for that purpose.
