HELP!!! Jeep won't start, then started this morning, Troubleshooting?

[bjlasota]

I'll try to write this up and hopefully you don't get bored. I'm pretty mechanically inclined, so any advice would help greatly.

This past Friday(9/27/13) everything was going fine until I tried to start my 2009 Jeep grand cherokee laredo, 4WD, V6, Gas. The car just clicked once and didn't do anything. So I got under hood, battery read 12.4v, horn, headlights and everything worked. Checked all fuses involving starter, and worked fine. Finally hooked up 150A charger, turned down a little bit, and tried to get a little more juice in the battery. The Jeep started right up after about 10 minutes on the charger, which got the battery up to 12.8V. Started the jeep a couple times over the weekend to move it around the driveway for guests, but nothing more than that. No issues. Left Jeep alone for whole weekend.

This morning(9/30/13) got up for work, Jeep started fine, drove 45 miles to work, worked all day, drove about 10 miles to walmart, went in for about 15 minutes, came out and jeep won't start. So here's what's going on in a bulleted fashion:

- Turn key to On position and let sit for a couple seconds. Lights on dash are seatbelt, engine, airbag, oil, and some electrical symbol between 2 backwards parenthsis.)z(
- Also hear fuel pump come on when key is in on position.
- Turn key to start engine and a single click, and radio goes dead. Lights remain on dash for about 5 seconds, then I hear a relay click again and the )z( goes off and the engine light begins to flash. The radio is back on at this point.
- There is no cranking of the starter or turning over of the engine. It's like the computers not even letting the car try to start. A single relay click and nothing happens.
- I took battery into both Walmart and Autozone and both their machines tested it to be ok. It's less than 2 years old.
- Hooked up with jumper cables and got battery to charge up to 13.8v, car goes through same sequence without a start.

- I'd like to avoid a mechanic, but my mechanic believes it's the starter. Somethings I've seen on a couple forums is it is the ignition switch. Is there anything I can test out in about 30 minutes using only a multimeter and some wrenches to pinpoint the issue beyond what I've already done? I've checked all fuses marked ignition. Any others that could cause this issue?
- Does anyone think it still could be a battery issue? When I pull the jumper cables off, the battery slowly drains without any accessories or lights on. But I didn't notice it dropping below 12.7v. Still won't start even with a jumper cable on at 13.8v.
- Another forum suggested it could be a bad key since it's the magnetic kind. I found my spare tonight and I'm going to test that first thing in the morning.

10/1/13 - I took my wifes car to work this morning and on the way, went through the following sequence:
- Used manual key to unlock door.
- Attempted to start car.
- Short delay, long enough to get the F word out, then a click and the jeep started right up.
- Shut off, got out, locked doors with remote.
- Unlocked doors with remote and started right up again.

So now the Jeep has started on a charger, and also with this unlock feature after sitting alone for about 10 hours. Anyone have a clue what may be going on from all the previous information? Is there any other troubleshooting I can do with a wrench set and multimeter, or is it time for this guy to go to a doctor?