Voltage Regulator Problem??

I don't have a ground strap to the frame, I do have one off the ground cable to battery to the radiator mount frame, two from rear of engine to bulkhead, one goes under VR mount. I do have a relay kit, not installed. I am trying to check out my VR's to see if I need a new one. All of them have different resistance readings. Thanks for the offer, all my VR's look like the original, two are solid state and one is mechanical. Mechanical is fld to ign 0, fld to base 0, ign to base 0. 1st solid state, ign to fld 15 ohms, fld to base 10 ohms, ign to base 4 ohms, 2nd solid state, fld to ign 9 ohms, ign to base 1.5 ohms, fld to base 10 ohms. Does that help any? That is information saturation for sure. Thanks for your time and help.
I would lean towards putting one of the electronic regulators in. Now if you Install a relay to feed the ignition terminal of the voltage regulator it should eliminate the flickering light syndrome. I went with an adjustable 70 and up style regulator made by a company called Roadrunner Electronics. There is an adjustment on the back of it that allows you to set your voltage. I set mine to 14.6 volts when hot and cruising.