my 85 318i keeps killin batterys.I've replaced the alt.But the ground wire was broken and had to make one.I used 8gauge wire and it is still not grounded.It sparks when you lay a screwdriver across the housing and touch any metal.did i use to big of a gauge wire?what gauge is stock?Any help on this would be very appreicated.I need to drive this car to work and back.So if anyone can help please respond.