My 06 Expy had what I thought was a battery getting weak. It would start but sounded like it didn't have a lot of life left. It is only a 2 year old battery so I put some water in it and hoped for the best. Wife got home this afternoon and when i went to put it in the garage it would not start. The starter engages but won't turn the motor over. I jump started it with another battery and it started. While letting it idle I noticed an ABS light and an airbag light were lit. I also noticed the dashboard battery charge gauge was not working. (needle on the gauge was showing "0" charge.
My first guess, a bad alternator,,,, Anyone have any thoughts before I remove it to get it tested ???
If you want to verify charging, get a voltmeter and after you get it started, measure the voltage on the battery terminals. You should have about 14.5v on the battery with it running. If you have around 12v, your alternator is not charging.
With the engine off, check the battery voltage. If should be around 12v. If it's something like 10v, the battery is bad and has a dead cell.