Dan, mine had a decal on the 4way itself with a wiring (color) code, it does sound as if you might have the wire on the switsh off a bit.
I know I've seen a diagram of the wiring for this on the web somewhere, but I don't remember where. Try starting at
www.nichols.nu
and find the 928 tips at the bottom of the page. I'm pretty sure where I saw it was on someone's site where they were changing to that later GTS type mirrors, you'll likely have to do a little creative googling to find it.