Car loses all power, clicking under dash after turning ignition

Hey everyone, I'm hoping I can get some kind of an
answer because I'm stumped. The other day my 01
Grand marquis ls totally died on me when I tried to
start it. The battery is less than a year old and
tested fine, and the starter doesn't click like it's a
dead battery. There's absolutely no power going to
anything. No door locks, dash, lights, nothing at all.
But the anti theft light still blinks and there's a
clicking sound coming out of the lighting control
module under the dash. The key chime still works
sometimes, but goes away when I turn the key.
Anyone have any idea if these would be related? Or
have experienced this as well? This is the second
time this has happened and I thought it was a fluke
the first time because it started right up after
sitting a couple days with the battery
disconnected. It's been about a year since it
happened before.