Help! Intermit. starting problem!!

Had the same problem with my 66 Dart a couple months ago.At the block on your firewall under hood,there,s a blue wire with yellow tracer,get someone to hold key on in start position and wiggle that wire.That,s how I found my problem with intermitten starting problem.I cleaned the box out of corrosion and crap,fixed it!Also bypassed ammeter.Hope this helps!