Mine is doing this too. She has been for a while. My alternator was replaced not too long ago and my battery *Diehard from 07* checks out OK. She also drops the voltage when I come to a stop or turn the wheel. It makes no sense. Nobody can figure it out. When I hit the brakes, it drops. When I throw her in neutral, it rises. Also, when you turn the wheel, the RPM'* are supposed to rise right? Well, mine drop. This doesn't make any sense to me. I've had her checked out by 3 or 4 people. Nobody can figure it out. I'm at the point where I'm saving money so I can replace her :(. I don't understand what it could be. Especially the whole braking thing. It makes no sense.

Well yours just sounds like under inflated tires-low power steering fluid (the rpm drop when turning).As for voltage SOME alts require a certian RPM range to perform as rated..When you hit the brakes the RPM drop therfore your alt spins slower and when in nuetral there is no resitance from trans so it can spin faster..Like i said SOME alts are like camshafts and have a certian operating range

i had the whole charging system checked the total output charge of my system was 13.75v....the alternator tested around 12.75v and it was tested with the ac on blasts to high,the engine reving for 5 sec with the ac on and off and with the headlights on...everything seemed to pass the test

My tires were all inflated perfectly when I had my last oil change. They did it for me. I don't believe my power steering fluid is low. I can check that. What I want to know is WHY is it happening. It shouldn't be. My car is the only car I've ever seen do this. I just changed my alternator not too long ago. The battery tested fine at autozone and my mechanic. Everyone is at a loss.

12.6=Fully charged battery
14.4-14.6= charging voltage

make sure the positive cable and ground cable going to your fuse blocks look ok. that happened to my grand prix se

Looking back at posts...

“battery meter jumping and back and forth especially when I’m idled at the light". "The car also feels like it wants to cut off". "It was also laboring hard to start” - neutral idle is better.

What was the tachometer reading at red light when the voltage was jumping? Does it seem to start quicker and idle better when cold (sits overnight)? when it’* laboring and hard to start do you mean you have to crank it longer?

Sorry if I seem stuck on a FPR lately but just did mine recently and had many of the same symptoms including voltage gauge. Maybe it is not battery/charging related and your engine is trying to flood and almost die at stops and low speed. Pull the vacuum line off the FPR after you have run the engine ,if you see or smell gas it is bad.

Honestly, yes. It starts extremely quick after she sits overnight and idles much better. What exactly is the FPR?

Fuel Pressure Regulator- here is a link I found that shows how check it ( about 1:40 into the video) pretty common problem.