I hear you, this particular system is really strange in terms of the wiring.
NEW UPDATE, I was buttoning things back up and just trying random things to suddenly find that there must be a break or loose connection in the lead or the 4pin...
Hey @roadsalt, awesome that you finally solved your wheel!
I'm still chasing my issue, essentially the same problem, good fuse, everything seems right but no switch light, no heat. I saw this new discovery of yours and pulled my steering column...