87 5.0 speed density. there is a connector coming out of the headlight harness right by the battery. it has 2 wires, and clips into a connector that has 3 wires. if it is connected my stang idles very rough. but if we disconnect it, it idles and runs great but it stops charging the battery. according to schematics i dont see why this connector would have anything to do with the charging system. does anybody know what this connector goes to/comes from? or why the vehicle reacts this way.