Crash,
The switch is very easy to replace, it is held in place by two tension arms, one on top and one on bottom. You can see a picture of the switch at this link. Simply use a pocket knife or thin blade screwdriver, pry the top part of the switch out and the rest will follow. There are two electrical connections on the back, then just pop the new switch in place. Total time, maybe 10 minutes. It will take much longer to get the part number and go get the switch... LOL
http://www.americanrvcompany.com/Sub...iler-Camper-RV
I'd check with a flash light and a mirror while you have the switch out, there's a reason it failed, probably from corrosion on the spring loaded rocker inside the switch. Check carefully to make sure your tank isn't leaking into that area, that could be a reason for the corrosion and switch failure. Then again, it could just be a bad switch, but I'd look to be sure.
Good Luck