...I'm not sure what to check...
A conventional 3-way light is wired like this. The hot line goes to one switch and two wires connect the two switches.
___________________ light
Hot_________/ ___________________ \_______?____
AC |
Neutral________________________________________|
When both switches are up current can flow through the upper line. When both switches are down current can flow through the lower line. If one is up and one is down, there can be no flow of current.
The X10 switches maintain a small flow through of current like the regular (SPST) X10 switches.
Do you or your friends have a voltmeter or a neon tester? In this case a neon tester (I'm not sure they're called that but they are.) was easier for me to use. They're cheap. A buck or 2. Maybe as much as $4.99 at Radio Shack. They're also a handy way to check if you really turned off power. I had to do some probing around to figure out which one was the hot line, then connecting it to each of the connecting pair till I identified each of them.
LABEL YOUR WIRES AS YOU GO AND BE CAREFUL WITH THE LIVE CURRENT!Tip from personal experience: Not all switches in the same box are always on the same circuit. I learned that one the hard way.
