Voltage
Thread Starter
Cruising
Joined: May 2019
Posts: 11
Likes: 0
Voltage
Hi the other day while I was driving my 1988 corvette
I noticed the voltage regulator when I was stop it would go from 12V to 11.7V and when driving it would go up to 12.7V or higher and com down again when I slow down or stop. Could that be a battery or alternator issue?
Thank you
I noticed the voltage regulator when I was stop it would go from 12V to 11.7V and when driving it would go up to 12.7V or higher and com down again when I slow down or stop. Could that be a battery or alternator issue?
Thank you
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
As well??? It's sounds like the ALTERNATOR (the internal regulator, probably).
Normal voltage at the battery (when engine is running and alternator is properly charging) is 14.7V when or if charging a cold/discharged battery, or 13.8 after under hood temp is hot and /or the battery is fully charged (and also hot).
If you're tallying "votes"
to determine what to change, +1 more for the ALTERNATOR. 
Normal voltage at the battery (when engine is running and alternator is properly charging) is 14.7V when or if charging a cold/discharged battery, or 13.8 after under hood temp is hot and /or the battery is fully charged (and also hot).
If you're tallying "votes"
to determine what to change, +1 more for the ALTERNATOR.
Le Mans Master
Joined: Mar 2004
Posts: 5,107
Likes: 171
From: Dublin CA
Agree with the above....alternator. It is telling your that it will be dead soon. Replace it now before your forced to in perhaps a bad situation. Normal charging should be 13.8 to 14.++. depending on what accessories you have on.
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Melting Slicks
Joined: Oct 2016
Posts: 2,024
Likes: 363
From: Central Alabama
While I don't disagree with there being an alternator issue, just go through and make sure your battery terminals are tight. I had a loose terminal and I was getting readings from 11.7 to 13.8. Since tightening them (had to replace one terminal bolt), I've had proper readings.
It costs nothing to check them.
It costs nothing to check them.
Racer
Joined: Jul 2017
Posts: 422
Likes: 53
From: PA
While I don't disagree with there being an alternator issue, just go through and make sure your battery terminals are tight. I had a loose terminal and I was getting readings from 11.7 to 13.8. Since tightening them (had to replace one terminal bolt), I've had proper readings.
It costs nothing to check them.
It costs nothing to check them.