2003 Tahoe problem

[Rabid]

Got into the wifes Tahoe this morning and have issues. Door open, key in the ignition and no noise. No lights on the interior came on nor key in the ignition beeping. Actually there was no power flickering on even when I turned the key a half turn. Normally the guages will at least move. Attempted to turn the engine over and it sluggishly turned over. After turning the key over constantly for about 20 seconds and pumping the gas, it started. The engine then loped between 200 and 500rpm on the verge of a stall. I popped the hood and checked the battery. Its green. The gauges show full battery charge as well. Then I revved the engine and the problem seemed to clear up a bit. The engine ran a little smoother and when I shut it off it restarted as it should. Quickly. The lights even came on the interior and the key in the ignition beep came on... So what is up? Moisture somewhere it shouldn't be? Alternator? Loose wiring?... Its been raining a lot lately and actually the other day I was driving it during the rain and noticed the engine loped when I came to a stoplight. ugh... Any help would be appreciated. Thanks.