YACT: Alternator voltage regulator problems?

[arcas]

Normally, my Honda Passport's alternator seems to put out between 13.5 and 14.5 volts. But I've noticed from time to time that it'll drop down to just over 12V. Let's say 12.3V. I've only seen it sporatically but when it happens, I'm in 4th or 5th gear, never in a lower gear. Engine RPMs don't seem to be a factor since I've seen it happen even at highway speeds. Letting off the gas slightly usually causes the voltage to jump back to ~14V but as soon as I accelerate again, the voltage drops back down to 12.3V.

This is only sporatic behavior, however. Sometimes it happens, other times, the voltmeter indicates ~14V like I would expect. There are no electrical devices in operation. In fact, turning on the headlamps is sufficient to make the voltmeter jump back to 14V or more.

Now, my understanding is the voltage regulator in an alternator monitors the electrical load and adjusts its output accordingly (which explains why things jump to 14V when the headlamps are turned on). But why does it allow alternator output to drop to 12.3V on other occasions? Is this standard operating proceedure and I've only now begun to notice?

It bothers me because 12.3V isn't really enough to charge a 12V battery so I'm afraid that when this happens, I'm not recovering amps spent during starting.

 

[GalvanizedYankee]

Only since no one responded I will give a guess..There is a ground issue to your voltmeter.

 

[Quixfire]

Honda uses a load-sensing charging system that only charges during specific operating modes, such as when the lights are turned on. When the alternator does charge, the voltage should range from about 14.2 cold to about 13.8 hot and loaded amperage should range from 40 to 60 amperes.

You vehicle is acting normally, but I would check your battery voltage to make sure it is charged up, it should range from 12.3 to 12.6 after one hour of driving the vehicle.