These intermittent electrical problems will drive you friggin crazy!

The only thing I can suggest is to unbolt all starting circuit connections, scape/sand everything clean, apply some dielectric grease, and re-assemble. If you do all that and with what you have replaced and still having problems, I'd start suspecting the starter and the solenoid on it. That you should be able to take to a good shop and have it tested.

"Never underestimate the power of human stupidity" - Robert Heinlein