Have you made sure that the alternator is putting out? "Was barely running and now won't turn over". One of two things,1) something else is causing it to run poorly and you simply ran the battery down cranking it over or 2) the brushes in the alternator have finally worn away and now it is running off of the battery, as the state of charge gets lower and lower in the battery the car runs worse and worse until it runs no more and of course will not crank over because the battery is dead. I would charge the battery back up, get it to crank over and run and then check you charging system output. You could even simply pull the voltage regulator out of the back of the alternator, two screws, and see if the brushes are worn away. If they are you will see that the inboard brush is worn away more than the outboard and the short one will not have that bright shiney surface on it an more. Just a thought.

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