Originally posted by: saxguy
it could be just the battery, but rather than replace the battery and had it ruined in a few days because of bad alternator, you'd better check the alternator first.
For all practical purposes, no, it could not just be the battery. There are precisely zero symptoms that indicate a bad battery here. Even if the battery were completely drained, once the engine has started, it will run perfectly and the alternator will charge the battery (albeit slowly).
What happened here is that the alternator died and because he continued to drive the car in that state (running everything off of the battery) he has drained the battery to a very low level, which is why he was experiencing electrical problems. I will be very surprised if the car starts after this. There are two practical possibilities. Either the alternator belt snapped (if the car even has an alternator belt, if his car uses a serpentine belt, we can rule out the alternator belt snapping because serpentine belts also run the water pump and PS pump so he would have noticed other malfunctions if the serpentine belt snapped) or, as is more likely, the alternator has failed. His battery probably
is dead by now though since he's drianed it severely and lead-acid automotive batteries tend to self-destruct if fully discharged, but that's not the cause of the problem, its just another symptom of it.
To the OP: What the heck were you thinking that you kept the radio on when the "charge" light came on? The
first thing that should be done in that situation is that you turn off every un-necessary electrical accessory. Turn off the radio, turn off the heat or A/C, dim the interior lights if the headlights need to be on. What on earth do they teach people in driver's ed anymore?
ZV
