The Stovebolt Site Forums The Shop Area The Electrical Bay Voltage regulator failure? Or something else?

I just finished installing all new wiring in my 1963 C10. Everything is working nicely.
I am pretty sure I have a faulty voltage gauge in my dash. It reads 15.3 V with the engine running. If I use a digital voltmeter, I get 14.6 V while the engine is running.
When the engine is off, I am reading 13.6 V at the battery.
My 10 SI internally regulated alternator seems to be functioning just fine, but that is the question at hand. Is it possible the internal regulator inside the alternator has failed and that I’m over charging the battery. My understanding is that this will lead to early failure of the battery and headlights going bad quickly.
I’m looking for suggestions besides buying another alternator. I wired the truck to do away with the factory voltage regulator. It seemed unnecessary to keep the factory voltage regulator, and it would have complicated the wiring process quite a bit.

Normal regulated voltage against a fully charged battery (very important!) is 14.7V, measured at the battery posts, not the terminal clamps. 10 amps or less of current flow into the battery at a fast idle is also a good indicator of full charge. Depending on where the dash meter is connected to monitor the voltage, a few tenths higher isn't a problem. To get proper regulator monitoring from the 10-SI, you'll need to be flowing 10 amps or less total current output from the alternator. A shorted 10-SI internal regulator will produce 17-18 volts at idle, and over 20 with the engine revved up.

a few tenths of voltage variation is pretty much nonsense- - - -the real indicator of proper battery charging is whether or not you're having to add water to an open cell battery frequently. Losing electrolyte level consistently is an indication of overcharging. Sealed batteries- - - -you're pretty much on your own there, other than the battery should be able to crank the engine easily, in very cold or very hot operating conditions.
Jerry