I had to manually flip the power switch a few times, from auto to manual to off and back (even though it was on auto all the time and the battery was charged as evidenced by a 3.8VDC check on the side panel) and there is plenty of propane in the 500 gallon propane tank. I flipped the breaker a few times. I pulled the fuse and it looked good. https://c1.staticflickr.com/9/8679/15815391388_9086fb0b88_b.jpg
Everything looked ok electrically, and, after a few flips of the switch, it turned on. Recently on its weekly charging cycle, it had been turning off and on after only a few seconds, so, that's probably related.
While the Generac not starting is one problem, the other oddity was that, once started, and seemingly running full force, the transfer switch(s) inside the garage were clicking for about five or ten minutes and then stopped clicking. https://c4.staticflickr.com/8/7505/16002089322_521ae182de_b.jpg
I opened the panels, but by the time I opened them, the clicking had stopped. https://c4.staticflickr.com/8/7508/15817034197_b2a2d214de_b.jpg
I took a video of the clicking, but I'm not sure where to upload the movie (it's a 24MB MOV file from an iPad) if needed. Here is a closeup of each panel - which seems to have a big solenoid inside: Left: https://c4.staticflickr.com/8/7522/16002089132_a30301e7ec_c.jpg
I'm guessing that the propane generator wasn't up to speed at first, for whatever reason, and that the voltage wasn't as high as it needed to keep the solenoids down, so, they were clicking? But I never heard that clicking before, and, the lights were running as soon as the generator kicked in.
Any debugging suggestions?