What is the best tool or method in your opinion to locate cable damage causing current leak on several cables supplying outdoor lighting as detected by a tripping GFCI breaker. (Or water in a light obviously). Is there a meter that can measure that directly with the power off?
Ohm meter, to detect foreign ground on the wires or the fixture. Water on the line or the fixture will show up as a high resistance ground, versus a good ground.
I usually have one of my kids lick their finger and run it along the cable. a lightbulb in the mouth helps.
