First off hello everyone. Have been lurking here since I got my 07 HHR a couple months ago but just registered. Love the car so far! Mileage is awesome! My other vehicles are a 00 4x4 silverado and a 00 semi-built Trans Am so I guess I should be happy with the mileage. My problem is that about a week ago while driving my radar detector warned me of a low voltage problem but no lights or any indication of a problem yet, then it did the same thing a couple minutes later and this time I did notice a whine from under the hood....still no light. I was heading to my brothers house so I just hoped for the best in getting there. A few miles down the road, the detector warned me again and now it wouldn't even work anymore. Then the car started showing voltage problems, first the steering, then radio, then warning messages for the steering, airbag, then the trans wouldn't shift anymore. Needless to say it completely died soon after. Luckily, I was close to his house and we pulled it there. I was as I thought the alternator and after changing it and getting it running again, I noticed when I turn the key on the battery light comes on but goes off after starting it so the light does work but why didn't it come on when the alternator went out? Having to reply on the radar detector isn't exactly what I'd like to do. Is there anything that could be causing the light to not come on when there's a problem? Makes me nervous about any other warning lights now. Thanks for any suggestions!

 

Welcome ...
You described the sound under the hood. If the generator is already new, replacing the drive belt is also (not expensive). If the sound continues, look for a source of sound from other consumers. It is unlikely, but a stuck air conditioner bearing can slow down the rotation of the generator.
The light may not light up. I don’t know the reason, but it is. I noticed one offensive feature of our car - the oil and battery light comes on at the last moment, when everything is already lost and corrections are almost impossible.

 

Welcome to the forum.

Thats pretty much the way our 2006 acted when the alternator died a few years ago - things just stopped working slowly over about a 2 mile stretch, but I think it did give a warning on the dash at the last minute. The stink and a little smoke out of the alternator was the best indicator that pointed to the alternator.

 

There is a battery light indicating low amps but not volts.
Have the battery load tested, or if it’s more than 4 or 5 years old , replace the battery.
the alternator failed possibly because of being over worked to run the systems.

 

The light monitors the condition of the "turn on" signal, not the output of the generator (GM calls it that, not alternator).

 

Well, the battery is only about 1.5 years old so it "should" be ok. Since changing the alt out, it's running fine again. Guess with a new one, it'll last a few years at least. Guess I won't rely on the light in case something were to happen. Funny thing is I'm working on a 07 Callaway Corvette and the same thing happened to the alt a few days ago, whine and all. Although the message center did tell me there was a low voltage problem and that car's been sitting for over 7 years. lol Thanks for the help!

 

It should be ok? But is it? Have it load tested.
same as , there’s a rest stop a couple miles down the road, there never is!

 

Yeah, better safe than sorry. I'm gonna pull it out tomorrow and have it tested. Can't hurt for sure.

 

They can test it while it is still installed.

 

Just drive to your local parts palace, they check it usually for free.