Is there a way to test if the electrical system of our Cat is grounded? I have been having problem with the Charging system of the Cat, it's like if I idle for a long time, the voltage reading drops drastically. I've had the alternator checked and the center I brought it to said it's fine. I'm just wondering what's the problem. The problem is worse when the A/C is on, and driving at night when the headlight is on. Anyway, I'm guessing that something is shorted somewhere or grounded. Any help is appreciated.