3 wire alternator putting out 15-16 volts

took out my non-op ammeter (wasn't hooked up) and installed a volt meter today. Tractor has a brand new battery that is fully charged. Why does the 3 wire alternator put out 15-16 volts constantly? Don't want to fry that new battery. Ideas? any more info needed? Thanks

(quoted from post at 20:38:37 03/20/10) took out my non-op ammeter (wasn't hooked up) and installed a volt meter today. Tractor has a brand new battery that is fully charged. Why does the 3 wire alternator put out 15-16 volts constantly? Don't want to fry that new battery. Ideas? any more info needed? Thanks

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he GM acceptable upper end is 1.52 volts. What is the resolution of your new voltmeter? What is the voltage difference between the two closest graduations? Is the quality/precision of the meter as good as the quality/precision of the GM regulator? Was your battery overcharging before the meter swap?
In other words, you are likely just fine.

I have only put 4 or 5 hours on the tractor since getting it. When I first got it I put my Fluke Multimeter on it and it was reading 15.5 volts. So it was overcharging before I put the volt meter on it today.

(quoted from post at 21:29:31 03/20/10) I have only put 4 or 5 hours on the tractor since getting it. When I first got it I put my Fluke Multimeter on it and it was reading 15.5 volts. So it was overcharging before I put the volt meter on it today.

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1.9%
You need more troubles, Sir.
P.S. I am serious, but if you just can't tolerate the voltage, the solutions are 1) new alternator, 2)new regulator, 3) new voltmeter. One or all ought to help you, or at least the selected combination.

Cutty,

I know this sounds like a crazy idea, but check the ground wire - see if it is making a goood conection. I had an old 71 ford torino, one day all the gauges went crazy, nothing electrical would work, car would drive but.....
after new battery - old one was being charged almost 16 volts, new voltage reg (ford said it was bad) - came to find out that the engine to frame strap wire had worn down to nothing, causing the voltage reg to try to "charge" the system through a wire that got too small, sounds crazy, but I took a coat hanger and rigged up a new ground wire for the weekend until I got a new grounding cable. Not sure if this would have anything to do with your system, but I will tell you that you can boil out your lead acid battery by "overcharging" it for a long period of time.

Cutty,.
Each time you start your engine, you pull a little amperage from the battery. Your regulator sees this and charges the battery to compensate. You appear to be worried about the high voltage reading you see just after you start the engine.

May I suggest that you let it run for twenty minutes and then use that Fluke to get a more accurate battery voltage reading. In so doing you are giving the charging system to equilibrate from the last crank-up. This will also give you a chance to compare the accuracy of your new dash gauge with a lab-grade instrument. Once the battery is back to full-charge status, the alternator output should level off. If you stay at 15+ volts and go no higher, you're still okay - just at the top end of the okay limit.

The only way to change the regulator output on IC circuitry is - unfortunately - to change the regulator itself - no adjustments on that puppy. I'd live with it, were I you, and after you use it long and hard on one day, just make sure the battery never gets warm from overcharging.

Almost like too much money, or any other good thing, long as the battery doesn't get warm. Think about it this way - yer lights'll be nice and bright . . . . . .

Good Luck

Dave Erb
New Holland, PA

Is the "voltage sense" wire in place from the alternator's output stud to the #2 terminal?

Are you relying on a dash gauge from "the land of almost right" or a quality voltmeter?