Okay, so I checked all the fuses on my Whirlwind, and lo and behold, at least one wasn't showing continuity.
F2 and F3 fuses on the Power Driver Board. F2 I believe was the one that definitely was not showing any continuity.
The F6 fuse on the Aux Power Driver Board shattered at one of the ends. I personally don't know if I was the cause, or if it was already like that and was so brittle it broke. Either way, that also has to be replaced.
All other fuses were good, though the fuse holders likely need a good cleaning.
Another thing I found was the battery holder was very...suspect. While there doesn't appear to be any corrosion damage on the board, the battery holder wobbles around and both the negative and positive contacts really look like crap.