Sorry, but I haven't done a compression test in a zillion years, and that was on my old TR6. I tried a search but couldn't find anything....

I have a 74 R60/6 with dyna electronic ignition. Do I have to ground the plug wires? Or do I just screw in the tester and turn the engine over with the starter button?
and I'm going to look at a 74 R75/6 with points- same question: what is the procedure, do I have to ground the plug wires?
Thanks so much-
Kat