Battery gauge riding at almost 19v

[PNWYukon]

The battery gauge has always been at 14 or a tick past, and suddenly today it is near redline, stayed there then, dropped a bit to say 16 or so. Any thoughts?

Otherwise nothing else is crazy and everything works fine.

 

[swathdiver]

The battery gauge has always been at 14 or a tick past, and suddenly today it is near redline, stayed there then, dropped a bit to say 16 or so. Any thoughts?

Otherwise nothing else is crazy and everything works fine.

Does that year have RVC (Regulated Voltage Control)? I think it does, and if so, for some reason the computer thought it wise to crank up the output of the alternator to keep your system running and charged up.

 

[DougAMiller]

Does that year have RVC (Regulated Voltage Control)? I think it does, and if so, for some reason the computer thought it wise to crank up the output of the alternator to keep your system running and charged up.

Yes, it does.

 

[Joseph Garcia]

I'd put a volt meter on it first, before exploring anything else further, just to validate what your dashboard gauge is showing.

 

[PNWYukon]

Started it this morning after reseating the harnesses and it went back to 14.2 voltage with no variation. Battery tested at 14.5 and alternator at 14.7 while idling.

Hope we don't have a gremlin in there somewhere?!

 

[OR VietVet]

That gremlin may be a voltage regulator starting to have problems or a diode causing problems. Typically when a diode goes you also get a battery drain when shut off. Keep an eye on it.

 

[PNWYukon]

After going in circles, it looks like it is officially called the Generator Battery Control Module by GM. We will see. The battery is not a year old, so will do some testing after it has been sitting to check resting voltage.

 

[PNWYukon]

Resting battery voltage is right at 12.73v according to the Fluke 77. Have not had another gauge spike since replugging the harnesses.

 

[OR VietVet]

Hope it stays that way but you know how intermittent problems can be. Maybe just the act of unplugging reseated something better. That is a WAG.

 

[PNWYukon]

Still no change from a steady state. Pretty odd, but has not moved a stitch from normal since reseating the connectors. Anomaly? Who knows.

Maybe a good practice is whenever you are messing around under the hood or dash, to reseat any harness/connector plugs? People swear by products like Deoxit also.