Check and clean as needed all of your grounds, the battery is a chemical based storage devise that makes the voltage that the vechicle runs on. The current flow from all batteries flows out the negative terminals into the system and returns through the positive side of the battery scope
If the grounds are not good it may lead to overcharging shruggy work wrench scope

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)