Was driving my 02 mustang last night then my battery just dropped voltage almost died pulled over and saw that the nut and bolt on top of alternator were glowing red hot. Tried to clean ot this morning and in the process of barely taking taking the bolt off it snapped with the nut on it. Is there a replacement piece for this or do i need a brand new alternator. Its the red plug with bolt that heads to battery. Fyi i battery and alternator tested at advanced auto said everything was good.