Well that sucks.
Have you tried tapping on the starter?
New ground goes to starter bolt, right?
And (I expect) the starter cable itself is good.
Jim,
Lil'Red is a '87 F250 HD, 4.10's, 1356 4x4, Zf-5, 3G, PMGR, Saginaw PS, desmogged with a Holley 80508 and Performer intake.
Too much other stuff to mention.