PontiacBonnevilleClub.com

Its starting to get that cold wave in january here in wi, and yesterday went to start car after work and car was idling and then the check gages popped on ,but then went off. I didn't think much about it, but then got down the road to a stop light, and as i was sitting there the volt gauge was in between 8-14, then dropped to 8 so I thru it in neutral, and revved to see if that would do anything, nothing. I then took off and the gauge popped up and stayed where it should all the way home. This Morning in the garage same thing, under 14 volts like 10-12 range? then as it was warming up it popped up and stayed there to work. Does this sound like a battery issue or alt? I think the Battery is like 5 years old?

Sounds like a failing alternator. Your car will run at 14v even if your battery is junk. However, a failing alternator can cause a weak battery to fail completely. If the battery is already 5 years old, replace both. With this weather the last thing you want is a dead car.

I'm with Andrew on this one. Sounds like an alternator. You can go get your car tested for free at most parts stores like Advance or AutoZone. I would replace the battery one way or another given the age.

It was kinda my thoughts too, so if it is failing even tho its reading right when it comes back on gauge would it still show up when their testing it now that its reading right and appears to be charging?

Shows my car uses only a 105 amp? That sound right?

Yes, only the SSEi uses the 140amp.

Sounds like a voltage regulator issue which means changing alternator.
As others have said, good idea to change battery. My experience is all bets are off for battery life after five years.

Alt switched, gauge went right up, tested old one and failed on dc bolts and stator test. I just they battery charger on my battery to give a full charge for now, I’ll see how it goes and if I can get by til spring I will otherwise I do have another battery out of my truck on maintain to use.

So Driving to work today alt gauge was doing some funky moving back and forth and the lights were flickering as it was moving sometimes under 14, but then right back up , kinda sweeping back n forth? I checked connections and everything is tight and plug wasn't loose etc.
Any ideas?

As mentioned, a charging system test needs to be done. The only other possibility could be a loose connection to the alternator, which by your account you have ruled out. Corroded/failing cables could also be a concern, but only after a full charging system test. If that is the case, it would likely show bad in the vehicle, but fine on the bench.