I have 35 watt kits. But it shouldn't matter. Did you check for a blown fuse? If it's blown, that's a sure fire tip off that the polarity is reversed.
Also, to clarify, when I hooked up my hid fogs, they did not work. I found the fuse to be blown. I replaced it and tried again. The fuse blew instantly. So I reversed the polarity going into the ballasts and replaced the fuse. Paydirt! They worked. But only if positive is connected to the negative side of the ballast and negative to the positive side. You get what I'm saying?
Let us know how it works out.