He should have a new battery, but that's not your problem.. (or at least it doesn't seem that way to me).. While the truck is running the alternator powers everything, but if that battery is sooooo far down, it could be sucking up all the available power trying to re-charge.. A new battery or waiting until that one is properly charged is a must..
The speaker should NOT be getting hot if it's not making music.. Is the speaker new? if not, maybe it's blown? See if the cone actaully moves smoothly.. Did the amp get hot as well? Could be a wiring issue, but I'm not sure what would cause a hot speaker if it's not a dual voice coil.. and even then, you would have to have one wired out of phase and on a seperate channel to cause it to overheat at lower powers and not produce volume..
Anyone else have ideas about the hot woofer?
(1) Alpine CDA 7892 HU ($214)
(2) 12" Pioneer Premier 1241DVCs in sealed MDF box (gonna glass them eventually) ($69 each)
->removing.. ->(2) 10" Pioneer Premier 1041DVC's in sealed MDF box (gonna glass them eventually) ($59 each)
(2) Lanzar Vibe248 1200 watt 2 chnl amps ($119 each)
It's bump'n GOOD!
You can lead a horse to water but you can't make a moron understand...