1999 s-10 battery problems ... alternator?

[zlarson]

my wife called me telling me the truck (1999 s-10) was clicking when she was trying to start it so I jumped it with my car and it started right up. got home turned it off and tried to restart it, dead. Put a new battery in last night, started right up and drove it around a bit. Go out to the garage this morning, completely dead. any ideas?

[mike2004tct]

Originally Posted by zlarson

my wife called me telling me the truck (1999 s-10) was clicking when she was trying to start it so I jumped it with my car and it started right up. got home turned it off and tried to restart it, dead. Put a new battery in last night, started right up and drove it around a bit. Go out to the garage this morning, completely dead. any ideas?

For a new battery to go dead overnight, I'd suspect a light (interior) left on.

In order to kill a new battery via a bad alternator, you'd have to drive a good 15 to 30 minutes with the lights on. But to be sure it is the alternator, put a voltmeter across the battery with engine off (should read between 12-13.5V), and with the engine running (should read between 13-15V). Less than 13V indicates a bad alternator, also over 15.5V would indicate a bad voltage regulator inside the alternator.

Good luck

[frehol]

If the alternator in not working you use to get a warning light (looks like a battery, red light) when motor is running. If you don't get in I say you should start looking for another reason for the dead batt.

/Freddy

[DelCoch]

Check the under hood light and the glove compartment light and make sure they're not staying on. Have you recently installed any aftermarket stuff, like a stereo amp that may be live all the time?

[DINO55]

My 98 blazer has a factory setting that shuts off all electrical accessories after 20 min... Headlights, dome or interior lights. (designed so you don't end up with a dead battery) I would think your 99 has the same...