03 Yukon - "Battery Not Charging" but intermittent...

[DonnieBrasco]

2003 Yukon

Last weekend got in the car and the battery light was on, the gauge was below the normal 14 volts, and it said battery not charging. Ok, so my first thought is alternator. Get out the multimeter, check the batter, it's only getting about 12 volts. So, alternator, right?

Still cranks and drives fine. The next day, about halfway through the day, it goes away and the gauge is reading the normal 14 volts.

Basically, it's always reading "not charging" when I first crank up in the morning. And it goes for a while. Drive to work, park. Drive to lunch, come back. Then when I'm going home in the afternoon, or later in the day, it goes away and the gauge reads 14 volts. Couple things...

1) Could it still be that the alternator needs replacing?
2) Could be a loose connection I suppose, haven't checked those, but it's weird because later in the day when it goes away, it's not intermittent, it basically stays good the rest of the day.
3) It could be a computer issue too? I've had weird, pain in the ass, computer problems for YEARS. So it could just be that?

Thanks.

 

[sumo]

Could be a pre warning of a failing alternator. You have a harbor freight near you? Pick up one of these and plug it in your accessory outlet. It will show you battery status when off and show you alternator output while running. This way you can constantly monitor alternator output.

 

[jaywoo65]

Autozone will test the alternator for free.

 

[Tonyrodz]

Could be a pre warning of a failing alternator. You have a harbor freight near you? Pick up one of these and plug it in your accessory outlet. It will show you battery status when off and show you alternator output while running. This way you can constantly monitor alternator output.

X2

 

[Fless]

Numerous threads here about weird electrical issues caused by bad grounds.

 

[shreksbrother]

Could be a pre warning of a failing alternator. You have a harbor freight near you? Pick up one of these and plug it in your accessory outlet. It will show you battery status when off and show you alternator output while running. This way you can constantly monitor alternator output.

That's cool, thanks for sharing!

 

[DonnieBrasco]

Could be a pre warning of a failing alternator. You have a harbor freight near you? Pick up one of these and plug it in your accessory outlet. It will show you battery status when off and show you alternator output while running. This way you can constantly monitor alternator output.

Awesome thanks for the heads up. I will be heading to HF today at lunch to grab one of these.

Autozone will test the alternator for free.

Yeah, I did that. But, like I mentioned, it's intermittent. So, of course, when I went to AZ to get it tested, it was saying battery not charging and the gauge on the dash was low, so obviously it said alternator was going back with only high 12s low 13s volts.

 

[M1Gunner]

Could also be contacts internal of the alternator once heated up expand just enough to make it operational. Then once it cools down those contacts retract and open the circuit or vice versa.

 

[DonnieBrasco]

So, it's still a little intermittent, but getting worse. When I pulled in the driveway last night coming home from work the battery was totally dead (but I hadn't been charging it at night yet). I charged it overnight and it's fully charged today, but I know it will go down again. I've ordered a new alternator, it will be here Thursday. Will I do any damage continuing to drive it two more days until I can switch out the alternator? I put it on the charger at night when I get home. And I don't drive more than about 15-25 miles during the day on weekdays. This battery is only about 6 months old, but I don't want to royally screw it up. Thoughts?

 

[M1Gunner]

No, that won't harm your battery.