05 avalanche. 2 batteries with factory isolator. all accesories on one battery and starter on another. the problem is my pilot one keeps beeping, reading under 12 volts. also my volt gauge reads about 12-13. mainly the pilot one beeps if i run the blower or a ballast pump, but with the engine running. i checked the batteries while the engine was running and i got 13.1 in both batteries while 12 not running. are these number to low or normal. maybe a bad connection on my gauges or is my alternator not working properly.
|