Weird Voltage problem HELP!
Thread Starter
Heel & Toe
Joined: Oct 2008
Posts: 15
Likes: 0
Weird Voltage problem HELP!
1982 coupe.
OK guys what should I look for. The voltage meter and the GEN light come on while driving, The light goes from dim to bright and flashes and back to dim as the RPM's go up and down with the engine speed. The volt meter does the same it reads around 15 to 16 volts and goes up with engine RPM. The voltage with a VOM is 12 to 13 volts with the engine running, the alternator shows to be working as it should, it gives a constant 14 volts at all engine speeds an alternator check shows the unit to be working correctly. everything thing else is working as it should. is the gage bad? then why is the GEN light coming on, could the voltage regulator be bad?
OK guys what should I look for. The voltage meter and the GEN light come on while driving, The light goes from dim to bright and flashes and back to dim as the RPM's go up and down with the engine speed. The volt meter does the same it reads around 15 to 16 volts and goes up with engine RPM. The voltage with a VOM is 12 to 13 volts with the engine running, the alternator shows to be working as it should, it gives a constant 14 volts at all engine speeds an alternator check shows the unit to be working correctly. everything thing else is working as it should. is the gage bad? then why is the GEN light coming on, could the voltage regulator be bad?
Race Director
Joined: Nov 2002
Posts: 12,142
Likes: 54
From: Taylor Michigan
excessive high volts will blow headlites and electrical components...16-18+ is way too high...the regulator is built into your alternator and you should have it tested {the alternator} to confirm this
Le Mans Master
Joined: Oct 2004
Posts: 6,314
Likes: 508
From: South-central Missouri
IF your voltage reading with a VOM is constant at the battery, as you say, regardless of engine speed, then I'm going to say your fluctuations are likely a connection - likley a ground point for the gauge cluster (or could be the connector for the cluster itself).
However, as the previous poster said, the voltage regulator IS inside the alternator. However, since your VOM voltage across the battery is steady, then that pretty much eliminates the regulator.
Far as the voltage "reading" the dash meter gives you...Sheeeeiiittt! They're notoriously bad about being particularily accurate. As long as your VOM across the battery reads around 14.7 ± 1/2 volt...I wouldn't worry about it. (14.7 =normal when cold, & approx 13.8 when fully charged and hot.)
Good luck
P.
However, as the previous poster said, the voltage regulator IS inside the alternator. However, since your VOM voltage across the battery is steady, then that pretty much eliminates the regulator.
Far as the voltage "reading" the dash meter gives you...Sheeeeiiittt! They're notoriously bad about being particularily accurate. As long as your VOM across the battery reads around 14.7 ± 1/2 volt...I wouldn't worry about it. (14.7 =normal when cold, & approx 13.8 when fully charged and hot.)
Good luck
P.
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
If the fluxuations are fast and you are useing a digital volt meter you may not see them. Get a cheap analog meter and see what it says, plug it in to the cig lighter when you drive around, see what it does.
Gould just be a bad ground or connection at the gauge or at the 2 wire connector on the alternator.
Gould just be a bad ground or connection at the gauge or at the 2 wire connector on the alternator.
