I posted this in the 4.0L section as well, I know it's double posting, just looking for as many responses as possible. Ok I have been having this problem for a while, so I will start from the beginning, my car fails to start in the mornings or after a period of longer than 12 hrs. or so. It started about month and 1/2 ago, thought it was just the battery since it was the original battery and it has almost 5 years worth of life, a friend gave me a new battery he bought I replaced it and the car had no problems for roughly 4 or 5 days, then it started again, I replaced the positive terminal, nothing, bypassed the capacitor in the trunk for the amp, made it worse (as the capacitor has almost enough power to start the car on its own), then went to a friend's house we checked voltage out of the alt. and we were getting right around 14.8v or very close to that, we stumbled upon something and thought it might be it, with the amp meter around the negative line, we jiggled it and the volts started to flux, so I replaced the negative terminal and upgraded the ground wire that goes to the shock tower with 4 gauge wire and still no prevail, also there is no draw when the car is shut off. I shut off my stereo everynight and it's not a shaker.

 

Perform an amperage draw test with everything "OFF" as normal.
You will be suprized at the amount of parasitic draw.
Enough to partially kill an already almost dead battery.
(Caps dont draw amps once they are charged)