Rednucleus

Good day - Our 2020 Tahoe 5.3 has consistently had gauge at 14v in all driving conditions. Wife's car; she reports in the last few weeks days where it runs all day below 14, sometimes to the next line (12v?) down. Then the next day back to normal. Here's a pic from yesterday. She says stays there regardless of engine speed or what's running at the time.

david starr

normal for late model trucks, see owners manual.

Rednucleus

Thanks David; I know it's technically in the normal range, but - we have put 25k on this rig since March 2020, and until recently, that gauge ALWAYS stayed at 14, or slightly higher after 1st starting. Never has it gone lower. Yesterday we started motor after sitting overnight, gauge went slightly above 14 as it always has after starter battery draw. Within 30 seconds, it was down to the line below 14 (12?) and stayed there for a 30 minute drive - even with stereo, heated seats, heated wheel, everything drawing current but no indication a charge was being generated. Then on the drive home 3 hours later, stayed on 14 the entire time. So, IMO something has changed, but since no idiot charge light is on, and no message from the service center, and no outward indication battery is draining, what's the next step for a diagnosis? I suspect a trip to the dealer is a waste of time as there's nothing telling me a code is being generated. And I have found with newer cars, "no code means nothing wrong" for the dealer's tech staff. I assume it' ok to put a mutimeter on the battery when I catch the gauge down and see if the meter agrees with the dash? If the meter says 14 at the battery, and the dash says 12, would that indicate a gauge cluster problem?