Additional starter woes..long

[Nick Lawrence]

"It's what you learn after you know it all thats important"

This starter spanked me.
My wife's '91 100 wouldn't start, at an "off site" location.  I did the proper voltage checks and determined it to be the starter. So I go home to get one from my vast collection of used parts. I checked one out on the floor with jumper cables and a jumper wire. Worked every time. Go back (off site) and install the starter, starts right up, I let it run long enough to re-program the radio, shut it off and NO START.
Go thru all checks again, still points to starter.   Measure all volts, clean and ohm check all grounds. Put it back together it starts right up.  Do the radio, shut it off and NO START.  
This time I did a proper diagnosis and whacked it with a big hammer. Started right up.
So back home to get another starter and all is well.

Nick  central Ohio