This is a handy little switch, but I think prone to problems. On mine, I had trouble activating the switch. Turns out the fuse at the battery was shorting out. They replaced it with a breaker.
Something else. Suddenly, after unloading the front compartment, my 12 V lites ceased to function. In a panic, I phoned my tech for advice. He suggested that I might have pushed it to the "off" position when shifting things around in the compartment. How stupid does he think I am, I thought. I went the compartment, and, sure enough, I had pushed it to the "off" postion while working under there. Go figure! I think the tech just rolled his eyes when I phoned him back.