On Tue, 16 Jun 2009 00:58:27 -0400, mm
wrote:


The only hope you have with a DMM is to connect the dimmer to a load and measure
it then; however, at that stage, if the load is a lightbulb you could simply
look at the bulb's brightness to get the same information.

It's a 3-way switch, so he won't know which one of them is broken?

If either of them are. If he didn't disconnect the hot wire and
forget about it when he was working on something else, for example.