There's not typically any resistance between the white/neutral (also officially called....the GROUNDED conductor) and ground. It eventually gets connected to ground. 100 foot of wire shouldn't have resistance of more than a few HUNDREDTH of an OHM.

An infrared camera isn't likely to show much.

What do you mean the "light kept shorting?"

You say " At the switch, I measure no resistance between the white and the ground". I'm confused. Am I not to assume there is a white wire connected to the switch being used as a hot switch leg?

You said NETURAL. A NEUTRAL is always eventually connected to the ground (perhaps with not a low enough impedance to be useful for safety, but your meter should pretty much show a short).

Not ALL switches are switch loops. And you never mentioned SQUAT about switch loops. Further, the feed to a switch from a switch loop if it is going to use the WHITE wire should have the WHITE wire connected to the HOT.

If you connected your meter while the power was on, you're likely to damage it trying to measure resistance with 120V across it. If the power is off, you might still read pretty close to a short. A 60W incandescent bulb is only a couple of hundred ohms. A CFL or some sort of low voltage fixture can read a dead short for DC (which is what your meter on resistance is measuring).

You've still not explained what the problem is. What are you observing before you start screwing around with the meter? Is the light going out? Is the breaker tripping?

Thanks to all that responded. Perhaps I jumped to conclusions.
1. Every time I turn the light on, the breaker trips.
2. I removed and checked the light fixture, and it checks OK, nothing is shorted.
So, to start over, how do I start to troubleshoot the circuit? Thanks,

Ultimately the diagnosis may be visual. Inspect the boxes and "contents" at the fixture and at the switch.
Have you operated the switch with the breaker ON and the fixture removed? Caution: energized exposed conductors are involved.

take the light fixture down and turn on the switch. Does the breaker hold? If so the fixture is the problem, if not you have a wiring issue between the switch and fixture (switch leg)

Not to be rude but from your posts you don't seem qualified to troubleshoot/fix this issue. How would it be an issue between the switch and breaker if it holds when the switch is off?

Please call someone.

This post was edited by hexus on Sun, Nov 17, 13 at 16:27

Problem fixed. Thanks.

...a wire nut had come off in the fixture box. Yikes!