Why not consider a FAILSAFE ON switch... These units work know matter what, as long as their plugged in... OR I like the failsafe on regulators even better. Even if the switch wire connection to the regulator is lost it works, your ON... Together with HD wire and connectors these things are tough to beat...

http://www.smart-fly.com/page6.html

http://www.smart-fly.com/page5.html

http://www.fromeco.org/Reliaswitches.htm