[nancygrl]

Ozzie....it's normal. It's known as "smart charging" First came across it when we had our 2010 Silverado. Read up on it and saw that it was supposed do what it does. On my drive to/from work the gauge goes from charging (14+ Volts) to what you have in your picture several times each trip. Doesn't bother anymore me since I know it's normal.

[CTS]

Its called Regulated Voltage Control (RVC) system

Voltmeter Fluctuation Condition
Some customers may comment that the voltmeter is fluctuating between 12 and 14 volts on their full size pickup or utility vehicle. Starting with the 2005 model year, light duty full size pickups and utilities are equipped with a new Regulated Voltage Control (RVC) system. This system reduces the targeted output of the generator to 12.6-13.1 volts when in "Fuel Economy Mode" to improve fuel economy. The generator may exit "Fuel Economy Mode" if additional voltage is required. This will cause the voltmeter to fluctuate between 12 and 14 volts as opposed to non-regulated systems that usually maintain a more consistent reading of 14 volts. This fluctuation with the RVC system is normal system operation and NO repairs should be attempted.

[Fraxum]

Originally Posted by 3.8TransAM

Due to emissions and mileage regulations signed by the doof in charge in 2012, we now have idiocy like "smart" alternators.

Hmm I guess we don't really need a planet to live on. Makes one sort of sense to me.

Back to the topic:

OP I think that is normal.