On Sun, 12 Feb 2017 07:56:55 -0800 (PST), trader_4
wrote:

Since it started with the install of the new, apparently aftermarket
radio, I'd suspect it's possible something is wired up wrong there.
These cars have all kinds of computers and screwing up something
with the radio could result in something else staying on. I'd
start with just disconnecting the new radio as an obvious test.

I agree. And the radio should be wired to the original radio power wire,
NOT the light wire for the radio dial light. OR connect it to the cig
lighter power.

To eliminate any power drain overnight, go to an auto parts store and
buy a battery disconnect switch. It mounts on the battery and the cable
goes to the other side of the switch. You just need to open the hood and
shut it off when you park for the night.