Honda Civic 2010 Alternator Voltage Regulator

issue: car needed a jump start after work, the battery was not completely dead but not charged enough to get the motor running

I had a diagnostic test done at Autozone, test reading: battery good, alternator regulator faulty

Since then I have driven the car several times to run errands and get to work,
so far no issues

car has 70K miles
can I trust the Autozone reading?
if repair is needed, are aftermarket parts ok?
Is it a repair I could try to do myself?

Looking forward to your answers.

A diy’er can do a basic voltage check with a volt meter probing the battery terminals. When the car hasn’t been used overnight, and before starting the engine the next morning, the battery should measure about 12.6 volts. After starting the engine , should measure in the 13.5- 15.5 volt range. What does yours measure?

Do you know what caused the battery to go dead the time after work?

I have no explanation why battery was dead. I have not checked the volt range.

I found this in an older post:
_Honda alternator is controlled by the engine computer so it cannot be diagnosed by any one that does not have a computer link to the manufacturer -

Is this a correct statement?


It requires a scanner with the correct program.


It’s correct, but a diy’er can still do some basic diagnosis, as mentioned above. If it fails that test, most likely there is a alternator or battery problem. If it passes the test, good chance the alternator at least is ok.

how about the Autozone test result? Is it just a guess?

The conductance battery test is not without fault, you can get different results from a battery after sitting over night. It is unlikely that you are driving around with a failing alternator, your weak battery would allow the vehicle to operate for just a few minutes without an alternator.

How old is this battery? Is there a warranty?

checked battery again with volt meter, bad battery-thanks

battery was at least 7 years old, Autozone diagnosis proved to be wrong-thanks

Good for you for getting the problem correctly diagnosed and repaired. Best of luck. Auto batteries as reported here rarely last more than 5-6 years, so you got your money’s worth out of that one.