I have been having starting issues with my Z, and I was wondering what exactly the smaller wire that branches from the large negative terminal wire at the battery does. Yesterday when I was cranking the car over, the wire got very hot and started to smoke! Could this wire being shot cause my car to have power for accessories but not have spark? Also, where is this wire suposed to be grounded to? I have it screwed to the body with the weatherpack fuse holder near the coolant overflow bottle.

 

That wire is connected to the fender on my car. Exact same thing happened with the wire to the point where it melted but it was while the engine was running. Anyways I had to replace the alternator and the wire, but as far as location I think it is exactly where it is supposed to be. Just an extra ground.