Hello,

I left a light on and my battery died last night. Had a buddy try to jump me with his car, and it didn't work. Called roadside assistance and they hooked it up to a battery pack and it started up no problem. While the guy had the charger on the battery, he noticed that it was running at 15 volts, which he said was high. I drove it down to autozone and they hooked up their tester and it said the battery was good, but the alternator was indeed running at 14.98 volts. Is there something wrong with my alternator? This is the first time I've had any battery or starting issues in the three years I've owned the car.

Thanks in advance!

-M

 

It's quite possible your jumper cables where either bad, or you didn't have a good connection. 15 volts is high, but my recommendation is drive it a few days, let the battery and system get to normal, then look at the output voltage.

 

Hello msypek,

We're sorry to hear about this alternator concern you're experiencing with your Sonic. To clarify, have you made your dealership aware of this? We would be more than happy to assist in setting up an appointment to have this checked out. If that is of interest, please send us a private message to get started.

Chelsea D.
Chevrolet Customer Care

 

I am pretty sure the voltage will be above 14 volts , when the alternator is charging a low / dead battery .

Is it starting & running OK , now ?

Measure battery voltage , now . Running & not running .

God bless ,
Wyr