16 volts charging 2004 Tahoe LT 5.3L flex fuel

[Maximus1]

I measured the alternator voltage at idle and it’s around 16 volts. Should I be concerned? I always thought that normal is around 14 volts charging. Any thoughts on this would be appreciated. Thanks

 

[CountryBoy19]

I measured the alternator voltage at idle and it’s around 16 volts. Should I be concerned? I always thought that normal is around 14 volts charging. Any thoughts on this would be appreciated. Thanks

I have a Buick that has always run 15.4-15.8 V, idle vs revved up doesn't make much difference unless the electrical system is heavily loaded at idle at which point the voltage will drop lower because it can't produce enough energy at the low engine speed. While it does seem abnormal, I've been driving my Buick like that for 15 years now and it hasn't negatively affected things. Common sense says you'll cook your battery; at least that's what I thought. But I haven't had to replace my battery any more than normal. IE, I replace the OEM battery when the car was 9 years old and just replaced the first replacement a couple years ago.

 

[SnowDrifter]

Does the voltage increase when revved?

What about if headlights are turned on?

What's the temperature out when it's charging at 16v?

Hot or cold engine?

Is 2004 still internally regulated alternator? Or is that when they started going to external regulation and put a current clamp on the battery cables?

Where and how are you measuring voltage? What are your exact numbers? "Around" is subjective, I need specifics

 

[sumo]

Your charging system is computer controlled. It looks at the battery soc state of charge, air temp, input commands like headlights, tow/haul mode and determine the output of the alternator. It can charge 15.5 but may jump up to 16v but should not be a constant 15.5+.
How’s your battery? If you have a weak battery that’s not holding a charge very well, they charging system may be trying to charge it at full output.

 

[swathdiver]

Did the GMT800s have RVC and EPM?

 

[SnowDrifter]

Did the GMT800s have RVC and EPM?

Some

Didn't pay attention to see what models would and would not have it. If it's year, package, based, or both