Shopping online for switches... Trying to figure out the easiest/cleanest way to wire up a temporary substitute for the lack of an "ACC" position in the van, and it hit me...
I'm an idiot
About two weeks ago, I wired in a relay so my permanently-hot radio would take a signal from my ignition. The new radio was pretty hungry at rest, and was draining the battery.
I found the switch, figured out were I was going to mount it, and was ready to go. As I got started, I realized that I had knocked the leads off the back of my cigar lighter, so I addressed that first. As I was sitting in the car (with no radio yet - since I hadn't installed the switch) the radio came on after I rested my arm against the radio.
The keys were in my pocket. That's impossible! Did I waste my time last week? Did I do it wrong? I was confused.
I turned the radio off, then turned the car on, turned the radio on, etc etc.. I cycled through the on/off sequence of both the car and the radio several times, and it was working as I thought. Then I turned the car off, and tried to power the radio on with the keys in my pocket. It lit up and said, "One hour play" and I ran inside to RTFM.
When I got back to the van, I got my tools, put them away, grabbed a well-deserved beer for a job well done.