Help! Multiple Electrical Failures when started - Toyota Sequoia

I need you help please. Here's the background. 2003 Sequoia 4x4 LTD w/ 121K miles. Just returned from the lake, 2.5hr trip, unloaded and let sit approx. 3hrs. Went out to move to another garage bay, started and put in drive and all interior electrical components went dark. No issues prior.

Doesn't Work Now:
-Instrument Cluster. NO odometer, NO functioning gauges, NO backlighting, NO transmission indicator
-Heater A/C Controls Front & Rear
-Power Windows
-Sunroof
-Radio
-4x4 Controls
-Turn Signals
-Power Outlets
-Rear DVD/Entertainment
-Basically ANYTHING requiring the key to be switched to the ON position

Here's what STILL works:
-Starts & Drives
-Headlight/tail/brake Manually turned on at switch
-Horn
-Keyless Entry. Locks, unlocks, chirps, flashes lights
-Door Lock Switch
-Hazards
-Backlighting on Heater Controls Front & Rear
-Dome Lights

I have physically inspected and checked continuity on every fuse in all locations under-hood and in the cabin. Battery shows full charge and no obvious burn smells noted anywhere within the truck. Volt Meter reading remains constant at 12.8v with the engine running or off and decreases to 12.4v with the lights switched on. Alternator does not appear to be coming on line. As I understand it, the truck "excites" the alternator when key turned to or passed accessory thus energizing the regulator which effectively tells it to start producing power. I do not believe that the alternator is the culprit as she starts and drives just fine and there is no difference to the issue at hand hooked to a power cart with a batt voltage of 14.5v. My brain tells me its something to do with the ignition switch or instrument cluster. I've searched high and low on this forum as well as asked "Mr. Google" all to no avail.

In a nut shell, I started it and something switched off all electrical items associated with the key being in the "on" or "accessory" position.

Ideas?

Thanks in advance,
Dave