Lets say you`re megging some wiring from a disco out to 15 hp 600 volt motor.A&C read ok B reads 2.5 meg to ground. A&C are open I mean when I say ok. I was set to pull in some new wiring.Someone says its fine well I figured we`d show him since we`d only blow a few fuses but it worked.Now my question is wouldn`t the right thing to do be pull new wiring?And second when using a megger or meg ohm scale on a multi meter what readings indicate a true problem is there a range.Thanks in advance all the wires were diconnected on both ends completly by the way.