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Low voltage service battery warning.
battery replacement 6 months ago. Dash says 14.4V but at times its fluctuates between 9-14V.
Car has no other issues.
I'm thinking alternator. I'll have to bring it in Monday.
Dash shows the charging voltage. It can be as high as 15 V after an engine start and should ramp down to around 12.7 volts after driving for a while.
Double check that the small black wire is still attached to the negative battery cable. It is often broken when changing a battery. The wire is important for proper charging.
New batteries can fail. I have seen bad batteries on the shelf - I ask for a quick test before accepting any new car battery.
Most stores like Autozone can check your charging system for free. I would pull back the carpet myself...
Thanks Ron. The black wire is good. If the dash shows charging voltage, then my problem is definitely the alternator. I've never seen it go below 12.7V. And with it dipping down to 9V I'm thinking either its not charging or the regulator is bad.
as long as I've had the car it's usually around 13 or 14V when driving. Tonight on the way home I had all electronics off and when I hit the brakes, the voltage went wonkers up and down. My guess, the extra draw created a drain the the bad alternator could not keep up with. Hopefully I'm still covered on my GM extended warranty.
So start this morning the car idled rough like it had a miss. Voltage was 14.4 before it started jumping around again. Car sat on the tender for about 35 hours. The service battery light did not come on this time. The tender did show the battery in the yellow when I plugged it in Saturday night. This morning it was normal in the green again.
Shop just called. Alternator charging fine. Battery holding a load. They can't figure out why the voltage display started doing this. They are going to look deeper in to it and call back later today.
Ok shop went deeper. Alternator bad verified by scanner and load bank. Cost $500. 1.5 hours labor. Having them do the oil change since it's due. So my total will probably be close to $1K with parts, labor, and wonderful NY fees and taxes
Just got a warning
