I found the gravity drain for the fresh water tank, and while doing that found the water pump and Plumbing Central. It's all under the forward seat in the "dinette." Electric Central is under the aft seat, so that makes sense. Pretty accessible, once you know where you're looking.
So now I know how to drain the fresh water system and how to put sanitizing solution in it.
The battery continues to hold its charge. The little fan arrived to help the refer cool down more quickly.
Time to plan the Bisbee trip.