Super Unique interior mods!

d_phlat077

So needing some technical electrical help if available. I'm posting here as a followup to my earlier minor interior revisions' post, as I don't think my question is worthy of a new thread.
I dropped in a Nissan charging port- dual USB's- into the center blank between my seat heater switches. Wired it from the passenger seat heater power (red and black); good clean solder connections. First thing I noticed was it seemed to stay on a bit after ignition went off. I had assumed (perhaps incorrectly) that these wires would be switched to go off with the ignition. Now it seems to only work first thing in the AM, [edit: just realized it only work when lights are on since they are set to "auto"/ first thing in the AM=dark] after the car has sat overnight. Wondering what kind of witchcraft is behind these factory wires. I suppose I could just remove and attach to a known switched set of wires but then I'd never figure out why this weirdness occurs... [edit: SO I found a source to wire footwell lighting so that it comes on and goes of with lights if anyone wants that- I DO ;-)]