Voltmeter & Bluetooth

[FrankJB]

Has anyone noticed their voltmeter readings when the hands free bluetooth is on? I noticed the other day while driving my '11 Sierra that the voltmeter drops below the 14v when the bluetooth is on. It has done this a few times,when the call disconnects the voltmeter rises. Could it be a big amperage draw?

[JB Z71]

Well, this is purely a guess. But perhaps it does it to make things quieter. Have you noticed if you make a call bluetooth, that it also lowers the AC then returns it to setting upon disconnect? I doubt it is a high draw. Maybe other things are turned off too to make it quieter the result being less voltage required? Perhaps somebody with a more concrete answer will chip in!

[brycer867]

I have a 08 6.0 and i know the alternator only runs when power is required. They engage and disengage in hopes to save in fuel economy. Not sure if your 11 is the same

[MikeNH]

I have a 08 6.0 and i know the alternator only runs when power is required. They engage and disengage in hopes to save in fuel economy. Not sure if your 11 is the same

My 2011 does the same and I've read somewhere it is for efficiency reasons as well. Bluetooth is very low power draw. The whole idea of it is that it's a low-power, localized communication system. That's how those tiny earpieces can last eons on a puny battery.