3G 130 Amp alternator

[2manymarks]

My 130 Amp alternator upgrade is charging in the high 14 and low 15 volts as shown by my handy-dandy digital plug in voltmeter. Apparently it is internally regulated as I do not see the voltage regulator in the normal place. Anyone know what's going on here and what to do?

[NYC LS8]

Mine always showed mid-14 volts on the Autometer gauge. That doesn't seem too abnormal to me. I did blow out a regulator in mine once from a dead battery, but I wound up replacing it from one at the local parts store.

[gadget73]

Mine runs about 14.7-15 normally. Yours is probably fine.

VR is attached to the back of the alternator, its the part with the 3 wire plug.

[1989LSC]

Whats the lowest it can be? Mine is and the mid-high 13's. Does that mean mine is bad?

[NYC LS8]

I thought the regulator on a mark vii was external and on the fender.

On the stock alternators, yes. The 3G is an upgrade.

[ekooke]

A car battery may take a little over 15 volts charging for a brief period when cold, but optimal cold charging voltage is more like 14.2~14.5 volts when cold, tapering down to 13.8~13.4 volts as the battery becomes fully charged (from starting). 13.2 volts or less and the battery isn't charging, merely sustaining.

[Bluegrass]

To a minor degree the battery will dictate the charge level especially if is it has some age and one or more cells are beginning to fail..
Example: a bad cell can't be charged up so the alternator voltage will always be a little higher trying to always satisfy the condition that it can't do.
The regulator tolerence may also play a part down to a tenth or so.
My 02 F150 runs at 14.4 +/- .1 at all times. The battery is about 6 mo old MC 750.
In the OEM design, the average running load on the alternator and the battery capacity had a bearing on the final running levels, charge rates and capacities..

[MichiganTeddyBear]

both my 3g's run in the area of 14.5 volts, a little higher during initial recharge of batt after cranking.

As was stated before, the condition of the battery has a lot to do with the voltage output by the alt. remember, its not voltage that charges a battery, but voltage differential that causes the charging current to go thru the battery and charge it. therefore, the more difference in voltage between the 2, the more current goes into the battery.