dead battery/clicking glove box
sorry if this is an 'old' problem, but i am new....here. 99 5.2L D with 9 month old battery and no problems starting. shut engine, ran into 7-11, came back out, turned key & there was a 'sound', kinda like 'bad battery connection'. symptoms appeared very much like a bad connection-for the most part. no start, clicking from starter, BUT interior lights were pretty dim. playing with terminals on battery got lights to brighten, dim, etc, but still nothing or click-click-click of starter when turning key. then from time to time a click-click-click behind glove box. somebody gave me a jump, truck started as if battery was DEAD-DEAD, even required feathering of gas pedal to keep it running, after a few minutes, idle was fine, jumper left, i put truck into gear & it immediately stalled. much cursing & kicking, same scenario as before-clicking glove box, clicking or nothing from starter & light brightness changing intensity. another passerby offered a jump, same thing happened-stalled when put in gear, then another jump start, and i raced home running all stop signs, red lights, etc, pulled into driveway & truck idled fine. volt guage in truck showed normal, all accessories on dropped voltage, revved engine & voltage increased, etc, let truck idle for 30 minutes, shut it off, & POOF. SAME THING. another jump got it to run & it repeated everything previous. i hadn't yet found THIS forum last night, but others suggested 'bad battery', so this morning i took it back to where i bought it, he tested it with handheld device, it showed 12.7 volts/GOODbut 'replace' under CCA heading. they gave me a new one, i installed it, truck started irght up-with no idle. 5 or 6 times before i could feather it to stay running & it has been running for an hour now. i shut it off & it started right up, & though it seemed to want to stall when i let go of the pedal, it stayed running.
now, my question is-IS THERE STILL A PROBLEM? & if so, WHAT? other suggestions besides bad battery were so obscure, i can't even find an auto parts store that has or even has heard of some of these parts-not that i am normally a 'parts changer'. terminal ends are all good, including on starter & ground to engine. what about alternator? 120k plus miles & probably more then its share of 'charging' duties. any way to 'test' alternator on a holiday weekend before the local auto parts closes at 3PM, besides 'just changing it'? any other suggestions?