Voltage
05-19-2019, 01:00 PM
#1
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
05-19-2019, 01:18 PM
#2
Team Owner
Pro Mechanic
Alternator.
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Elpica81 (05-19-2019)
05-21-2019, 12:03 PM
#6
Le Mans Master
Member Since: Oct 2004
Location: South-central Missouri
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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.
05-21-2019, 01:28 PM
#8
Le Mans Master
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.
05-21-2019, 03:54 PM
#9
Melting Slicks
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.
05-21-2019, 04:02 PM
#10
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.