You're testing the coil, not the entire vehicle. Yes, you should have no continuity between the primary/secondary windings and the metal of the mounting tab.I get stopped on my first check...
Step 2...Is it just looking for infinite resistance to the mounting bracket itself? Wouldn't it want infinite resistance all the way to battery negative then?
That would also mean no continuity all the way to battery negative...but each inch of conductor, each connection increases resistance and makes it harder to determine whether or not there is continuity. So testing at the coil mounting tab--and leaving it at that--is the logical answer.
Kinda guessing you're getting false/flaky readings which may or may not be based on some sort of weird capacitance/coupling between your meter and the vehicle.I'm getting flaky readings in the Megaohms readings and sometimes infinite when I scratch the mounting bracket.....I'm not sure what's going on.... But from negative battery cable terminal ...not connected to battery, I'm only getting about 4 megaohms pretty consistently... Getting flaky high megaohm readings at various ground points/metal......Do I have a paint or coating issue?
Or bum test leads.
Or maybe a bum meter.
When my meter gave me crazy results like that, I contemplated sending my multimeter back to Fluke.just checked again and it really looks like I'm getting about 7megs at that first #1 in the picture test...
Got about .6ohms on the second test....and it was flaky..My meter seems solid...but it's almost like I can't get a good connection...even on the second #2 test.... really had to dig around to get a sweet spot for the reading....
jeez
even my #3 test is flaky ....going from low ohms to infinity and back to 10megs...all over the place....wtf?
Instead, I put different meter leads from a cheap multimeter into the sockets of the meter, and the crazy readings stopped.
That lead me to buy new, quality meter leads. Amazon has more than a dozen brands; be sure to get silicone insulation not PVC.
As for ohm readings when you're expecting a result under about 5 ohms--and certainly under one or two ohms--you'll need to measure the resistance of your test leads and subtract that amount from your meter reading. My new test leads have 0.2 ohms all on their own. If the meter shows 0.6 ohms, I'd have to mentally adjust that downward by 0.2 ohms for a true result of 0.4.