Robert, Ground points are all over the car. In your service manuel and you can find the major points. As far as the alt.meter diping below 13 volts. Keep in mind that the meters are appx. 1/2 volt on the low side average. The real question is, what happens when you speed up the idle. The new 140 amp alternator I have kicks up above 13 volts with everything on by just barely touching the foot feed. If you drive a lot and the car runs below 13 volts all the time, then there are some things you need to do. John vin 11004