ive had an intermittent electrical gremlin where my Dart won't get spark and won't start. Last time, there was a dead connector in the big plastic connector in the passenger side of the fire wall, solved by jumping the wire...I think. ...the under-hood wires are pretty brittle/grimy looking in general and I think it's time to investigate a new harness. How bad is this job? What are the hardest parts? Also, the harness is pretty expensive, correct? Any insights are welcome!! As you can tell, I'm in the dark here.