Join Date: Mar 2002
Location: Austin, TX, USA
Re: Connection between Alternator and Battery
It probably started as a bad connection in the crimp or between the nuts. The bad connection caused it to get hot. After prolonged heating, the insulating washer melted through and let the stud contact the case. As it arced over the stud got hot enough to melt everything and a scorch the metal stud.
Disconnect the negative ground cable immediately to prevent a fire. You may be able to rebuild the alternator. When you hook everything back up, make sure the metal is bright and clean. Put a dob of dielectric grease on it to keep the oxidation at bay. Those rubber boots they originally came with are also a good idea since they not only protect a high current power source from accidental shorts, they also keep the weather out.
68 Coupe, 350 w/ Edelbrock Performer RPM heads, cam, intake, 700R4, Dave's small body HEI