1999 GMC Sierra low voltage on dashboard gauge

I KNOW I KNOW!

HAVE THE BATTERIES AND THE ALTERNATOR TESTED AT A POPULAR AUTO PARTS STORE. THIS CAN BE DONE WITH THE ITEMS STILL HOOKED UP IN THE VEHICLE.

YOU KINDA NEED A LITTLE MORE OF A TEST THAN A VOLTMETER OR "IT SEEMS TO WORK"

AND THIS IS THE PLACE TO START, BEFORE YOU GO A THROWIN' A BUNCH OF $$$ AROUND!

ANOTHER TIP, SOME FELLERS ARE A BIT BRIGHTER THAN OTHERS, SO HELP 'EM OUT IF THEY GET ALL FLUSTERED, WHEN TESTING THE BATTERIES, ONE OF 'EM MUST BE UNHOOKED FROM THE OTHER, OTHERWISE THE OTHER BATTERY WILL INTERFERE WITH THE TEST. (SEEN THIS CLUSTERED UP, MANY TIMES, WITH THEM DIM FELLERS)

SURELY, THE BATTERIES STILL HAVE WARRANTY

THIS NEXT LINK MAY HELP OUT ALSO. READ HOW TO USE THIS TECHNIQUE EFFECTIVELY (MAKE THE ORDERS COUNT) SHOULD YOU NEED AN ALTERNATOR OR ANY OTHER ITEM

https://www.2carpros.com/questions/2001-dodge-neon-milage-just-want-put-fliuds-their-locations

YOU MIGHT FIND A BETTER CODE ON THE NET, "TRT30" SEEMS TO BE THE BEST THING GOING NOW (FOR ME ANYWAY) (A124 STILL WORKS, BUT NOT THE WAY IT USED TO) IF YOU DO LIKE ME, I FIND AS MANY AS I CAN, THEN DO A TRIAL RUN ON THE SITE TO SEE IF IT IS STILL VALID OR DOES WHAT IS PROMISED. THIS CAN BE DONE WITHOUT INSTALLING YOUR CREDIT CARD NUMBER.

RETURN HERE WITH GOOD NEWS!, OR ANY INFO YOU COLLECTED AT THE TESTS THAT MIGHT AID US, SHOULD WE NEED TO CONTINUE.

THE MEDIC