50/60hz Switch Problems

[FlamingBee]

I have added a 50/60hz switch to my Saturn. I am using a DPDT switch. I have soldered it in, and i tested it in one position, the 50hz one (well, its at 0v anyway) and it works fine. However, when i throw the switch i get a high-pitch screeching noise (not that loud, just very high pitched) and no visual. Any idea what i could have done wrong? I'm kind of worried that i will be stuck with a switch on it that doesn't (fully) work as i have cut the track and whatnot . (Well at least the saturn WORKS). Help would be greatly appreciated.