I have the weirdest problem, and no one has an answer!

Many times, when I go to downshift and am coming to a stop at a red light, my battery light comes on. When I start to move again, the light goes off. Sometimes, when I start my car, the battery light will come on, and then when I start to move, it goes off. Most of the time the light comes on when I am downshifting and slowing momentum…and goes off when I pick up the pace again. The battery was tested, and the crank amps are around 400…but the car starts just fine. Please help, because no one has an answer for me…

Has anyone tested the charging system? The light means there is an issue with the alternator.

Diva, Has Somebody Checked All Ground Wires?

Perhaps a ground, like the ones that “jump” rubber motor mounts is bad. The engine movement could make it and break it. I’m sure the battery cables were cleaned and tightened, right?

I’d experiment with one cable from a pair of jumper cables and add a good known ground along side other ground wires and see if that changes anything.

Does it occur all the time or is it more likely to happen when you’re running more electrical equipment like heater / air conditioning blower, lights, radio, wipers, etcetera? Have you tried turning off as many things as you can when the problem is present?

What model year is this Solstice?


There’s nothing weird about that. It’s a common symptom of a dying alternator (or bad wiring to the alternator).

It just happens when I start up the car and that is just occasionally…not all the time, and also just when I am coming to a stop and/or downshifting when I’m coming to a stop. I’ll have to try the grounding idea…no one mentioned that yet. I’ll also go to a shop and have the alternator system checked/diagnosed. (It’s a 2007, by the way.) Someone also mentioned cleaning the throttle plates, but I don’t know how valid that idea is.

+2 Tester.

Were we betting beer I’d say voltage regulator is dying.

Is there a way to test that, or no? I just want to exhaust all options before I jump in…considering I’m out of warranty.

Same answer to you though…how can I diagnose this thing? Is there a way to isolate the alternator system and test it? I hate not having warranty…

Physically check all the connections to the alternator, including the ground strap to the engine. If they are all good, then remove the alternator and take it to a parts store for free testing. Alternately, get a voltmeter and connect it while you drive. If the voltage goes below 13V or above 15V, then the alternator (or the voltage regulator inside it) has a problem.

“Someone also mentioned cleaning the throttle plates, but I don’t know how valid that idea is.” Unless your engine is trying to stall or you are having other engine problems, then this is not a valid idea for this problem.

Yes it can be tested, the alternator needs full field and system tests, this will determine the root cause - alternator or regulator. Either way you’ll be replacing the complete alternator if it’s faulty.

I agree with the others about the alternator as being the trouble. First, make sure the fan belt to it is tight. Hopefully that is the trouble and it’s a simple fix. Next, check the connections to the alternator making sure none are loose. The main lead to it is always hot to the battery so if you work on that lead first remove the negative battery lead before you work on it so there is no possibility of a short to ground. If those things are ok then the trouble is most likely inside the alternator and it may need to be swapped out. Your vehicle is fairly new though and most alternator problems occur after more years have passed. But even new ones can have trouble at times.

It seems you should still have some warranty left unless you have more than 36k miles on the car. You also can purchase an extended warranty if you like for the car but a lot of folks think you are better off saving the money you would have to pay for the warranty coverage and use it to help pay for repairs that come up over time. If you plan on keeping the car for a long time you might want to purchase a warranty. It may pay for itself over time and save you money.