And solution has been found! Fuse #7, a 5A fuse, was the culprit. And you'd never know it, since that feeds power into the radio. Apparently the second wire at the radio power plug (CI 23 per the manual) is feeding the voltage regulator. I still don't have oil or temp, I never have. But having a fuel gauge is necessary, and that'll be enough to get me to Carlisle.

Well, that and some goodies from Firm Feel that should be on their way ASAP.

Thanks for the assistance!