Alternator Typical Operation?

[Soak_n_Fused]

I have an 05 f150 5.4 3v

I was curious how many for owners watched their voltage closely?
I am not sure if I have an issue or not. I noticed the headlights bright and dim every now and again so I decided to put in a volt meter.
I watch it run most (60%) of the time run from 13.9 to 14.1v which is right where it should be
Now and then (maybe 30%) it will dump down to 13.1v
And pretty rarely but once and a while it will ramp up to like 15v

I know alternators run a little higher voltage in the cold temps than in the summer
I was really concerned about these voltage swings so I checked all my wires and grounded everything well.
I do not have any battery light come on or anything from it and the gauge doesn't move a ton back and forth.

Do these things run a high float charge then dump off until needed again?
Am I missing something Or is this normal operation?

Thanks

 

[mk378]

The modern "smart" charging systems command the alternator from the PCM. Depending on conditions they will vary voltage in a range approximately from 13 to 15. Dropping to 13 reduces load on the engine in some situations to increase mpg or get more horsepower to the wheels.

 

[WobblyElvis]

Charging systems have changed over the years. Regulating the voltage used to be a function of the alternator alone but not any more.
info here
http://www.diagnosticnews.com/are-you-smarter-than-a-smart-charging-system/

 

[Donald]

Is the meter your looking at a good multi-meter or a dash board gauge, or the free one you get at HF?

As other have said the PCM controls the alternator these days.

 

[TFB1]

Originally Posted By: Donald
Is the meter your looking at a good multi-meter or a dash board gauge, or the free one you get at HF?

As other have said the PCM controls the alternator these days.

Don't knock those HF meters, I have three and all parallel a couple $400+ Simpsons I used in electronics troubleshooting...

 

[Soak_n_Fused]

I Use two forms actually one of them is on my edge evolution tuner the other is a fluke dmm
well then the gauge as well so actually 3 but that's analog