Hey JD,
I don't know a thing about 72's, but out of a shear desire to help after that good natured ribbin :), I imagine your hot wire (not ground) should be coming from your fan speed control. If you don't already have one, get a cheapy harbor freight multimeter. I got mine for 10 bucks with a coupon and it works great. That's probably the first step to any electrical work.
