Yup! .... If you lived in the rust belt the answer would be quite apparent...I strongly suspect that you have a couple really crappy ground wires!...Cure #1 , get an 18" battery cable with the bolt fittings on each end...bolt to block on passenger side useing any accessible bolt on engine, and on the inner fender as well ... be sure to remove the paint around the bolt hole for good connectivity. Cure #2, there
are 2 wires going to the starter, A hot and a ground. the hot should have a good , clean connector and solid insulation (it gets burned sometimes) If not , crop back and solder splice some new wire /connector. Mechanical splices here are not acceptable. The ground wire needs to be cropped back a few inches, and a new connector applied as well. you can remove some insulation , and considering the age , youll have at least 3" of corroded wire there.. The Idea here is to remove/. minimize the corrosion, which is causing resistance here. A final cure #3, would be to replace the starter, if all else fails, and then I recommend a new Hitachi mini starter, as its only a few bucks more, has a higher tork output, and is 15 times better than any rebuilt you can buy (its the labor/ effort to remove and install the bugger thats the killer)...In any event , good luck, and let us know how things work out
