I was thinking more along the lines of a broken ground wire, high resistance wire, etc. I'm well aware of how to check a ground using a meter, but for 90%+ of the wiring problems that I see, it's pretty easy to supply a known good ground with the power probe and see if the component works.Agreed (as far as nearly worthless ohm test)
As far as checking grounds with a meter, pretty simple.
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The starter solenoid on our Peterbuilt that I talked about is a good example. A quick check showed that I had power to the solenoid when cranking, and the meter showed almost full battery voltage so we know that the positive side of the circuit was good. I hooked up the pigtail to the negative side of the solenoid (which supplies a known good ground), hit the positive side with B+ from the rocker switch, and the truck cranked over just fine. At that point, it's pretty clear that it was a ground issue, but the truck was running and I was able to drive it into the shop to check things out further, where I found a badly corroded ground wire. Much faster then trying to find the other end of the wire to do a voltage drop on the ground side of things, especially working outside in the snow.