Electrical Gremlin

[Daves73]

I have a little problem I'm hoping someone else has found an answer to... My 73 vert is charging at idle 15 to 15.1 volts under as much of a load as I can put on it. (headlights). New 60 amp alternator grounded to same bolt that grounds the regulator. New electronic regulator - grounded. New battery - tested 14.4 volts when I put it in the car. Engine is grounded via battery cable from block to crossmember. I know it's supposed to be charging around 13.7v. I really don't want to cook anything with too much voltage. I believe this is also causing a slight issue with my new Pertronix ignition. Anyone have any thoughts on what I may be missing?

Thanks in advance.

 

[Don C]

A fully charged battery will measure 13.2 volts, with no load or charger on it. When the battery needs a charge the regulator will apply up to around 14.5 volts when charging and current up to the limits of the alternator.

If your battery measured 14.4 volts with it just sitting there I would question the accuracy of your voltmeter.

If your voltmeter is accurate, you are correct, that 15+ volts is too high, may boil your battery, which not only damages the battery, but the acid won't do your engine compartment any good, either.

A new voltage regulator doesn't mean it is any good.

 

[Daves73]

A fully charged battery will measure 13.2 volts, with no load or charger on it. When the battery needs a charge the regulator will apply up to around 14.5 volts when charging and current up to the limits of the alternator.

If your battery measured 14.4 volts with it just sitting there I would question the accuracy of your voltmeter.

If your voltmeter is accurate, you are correct, that 15+ volts is too high, may boil your battery, which not only damages the battery, but the acid won't do your engine compartment any good, either.

A new voltage regulator doesn't mean it is any good.

I took your advice and found a different volt meter. 13.1v not running. 14.3v under load at high idle. Do you think it's still too much?

 

[Don C]

No, that's in the normal range.

 

[Daves73]

No, that's in the normal range.

Thanks for the help

 

[midlife]

Perfect. Throw the other DVM away; it is untrustworthy. FWIW, I've never seen one read that far off, and I've owned 9 of 'em and used probably 10 more at work.