FML, yesterday the battery on the wife's Armada took a crap. No worries, since it was the OEM i thought to myself: "it's been three years from the prior owner, might as well, swap it". So, I got her (because she's a she) a red top. Next day, wifey drove to work at 6am on this stupid 5 degrees weather, she gets off at 3:30pm... And The darn thing wouldn't start!!
Went to the rescue... took the battery out... Recharged it and voilà!
Well... I drove home and I am here looking at the percentage dropping.WHAT THE F**** IS GOING ON WITH THIS DARN THING??? AAARRRRGGGGHGGHH!!!!!!!!!!!!
I been taking each fuses off and testing the voltage with a multimeter. Nothing yet. I'm going to take it to the dealer tomorrow since still is under warranty.
Look at your dash while it's running, if the brake light on the dash goes on, Alternator is going. if it is the alternator, it should be under warranty since you stated that it is, if it's not under warranty, be prepared for a hefty bill, cause that sucker is a pain to change out.
An easy way to test the alternator is to start the vehicle, turn on the head lights, pull off the negative on the battery. If it stalls your altenator is bad.
You can also take it to AutoZone or advanced auto or simular type place and have them test the alternator. They do it for free and have a cart with the test equipment that rolls right out to the car.
you need to get a multimeter. They have them at Sears for $20.
Run the car at idle and set the multimeter to voltage measurements. Put the black test probe on the negative and the red probe on the positive. The battery should be 14 volts while idling. If it isn't at 14 volts then you have a charging problem. Either the alternator is bad or you have a bad battery cable. It is common for the negative battery cable to corrode especially if you live where it snows.
Found the answer for this nonsense. Here is my hypothesis:
The wifey's ride has Viper SmartStart. When the rides shut off after 25 min or so, the headlights stay on unless a door is open because she leaves them in Auto. I usually start her ride before she gets out of work at 3:30pm. Lately she been getting out at 4:00pm, so lights stay on till then and they are HIDs. Of course the battery is going to take a crap, proven cuz i tried this at home
Sorry guys for the long story.