Amp meter shows overcharging

More than likely your voltage regulator, but check and clean your battery cables and battery terminals. Then check the voltage of your battery with the car off and the doors closed. Watch to see if it's losing voltage. If it is, then disconnect the negative cable and see if it is still losing voltage. If it is then you have a bad battery. If it isn't, then you have something drawing power when it shouldn't. Then the fun begins while you try to hunt the draw down. Good luck with it. Hope it's something simple like the battery or voltage regulator.