Long time no see! Anyhow, have a little problemo with the 4.6HSE...
She's been good lately except for the other morning when I went to start her and was met with silence. All lights lit up on the dash and the key beeper was loud and annoying as always but nothing further when the key was turned to the start position, not even a click from the starter. So I got my trusty Fluke 87 out and put the probes on the battery terminals and watched the screen when I turned the key to start and noticed a voltage drop to 11.5 volts. Bear in mind that the rig has had a mysterious battery drain for quite some time, which, if it's driven daily, isn't a problem but if it sits more than a few days, will kill the battery completely. That being said, I've charged it up several times, kept it on a trickle, etc...and I'm wondering if I have perhaps killed a cell or two in the battery, so that when it is asked for a high current, it can't produce.
P.S. I should add that the positive AND negative cables are both new within the last year, along with the fuse box and alternator.
Pretty much every time I've had a battery go its been after some use and then some abuse. ie lots of cranking to try and start an unresponsive engine. When ours was in the body shop they left a light on and discharged the battery. Within a few weeks the battery failed. Yours seems a little new to fail so soon.