We have gone from a no start to a no or intermittent crank issue, and eliminated the starter most likely.
I call ignition switch, or resistance in the starting circuit due to 30 feet of old wire etc.
A relay back by the starter can do wonders and is a very, very common fix, some places probably still set the "hard start kits" that include a $5 Ford starter solenoid. (a good 30-40A std cube relay also works, but has to be kept dry)
RE: Ground strap:
Your DVM doesn't pass any significant current checking resistance. The ground strap will see 150+ amps.
I had a 76 Rabbit (Mk1 Golf everywhere else) with a annoying slow battery discharge issue, alternator worked great, (new) battery would not charge properly.(disconnecting it when parked did not help matters, no slow discharge)
Ground strap looked fine and passed the tug test and ohmed zero...
Momentarily shorted the battery to ground jumping it one day (hit front bumper with jumper cables) and later found a speedo that went to >90MPH with any fwd motion...
It blew the little spring in my speedometer..???
The ground strap ohmed fine but couldn't pass any current.
The dead short to the body passed enough current through the spring in the speedo to pop it like a fuse, via the speedo cable. There was some resistance in the braid.
Braid traps water and contaminants.
Braid rots from the inside...
Braid sucks.
Replaced the woven ground strap with a short hunk of battery cable, and replaced my speedometer.
Charging problem (and a whole host of other random electrical weirdness) all went away.
I run TWO 000(0?) ground welding cables off the trans, both sealed swaged jobs, one to the body and one to the battery.
I still look at them whenever I'm under the car.