Rich,
As I said in the Chat room.
There is a tester that you can hire to test the resistance of the rod to Earth, in relation to 2 other rods placed at least 12 foot from the in-situ rod.
What this tester does is gives a comparison of earth resistance of the two other electrodes and tells you how good the in-situ one is.
If you think you have a failing ground rod, it's probably best that you replace it, as a precaution.
BTW,Rich, what brings you to this conclusion?.
A poor connection can do the same thing as a bad rod.
Galvanic corrosion, get your metals right. [Linked Image]

[This message has been edited by Trumpy (edited 11-14-2006).]