For a properly installed three way system to work, you need a three wire
cable to go from one switch to the other. sometimes this cable doesn't go
directly from switch box to switch box, but instead, goes from each
switchbox to the junction box that the light fixture is attached to, and
splices are made there. If your system did indeed work properly after you
installed new switches, but not now, you have a loose connection somewhere.
It could be at either of the switches, or in a wire nutted connection in
either of the switch boxes or in the lighting outlet box as Frank ketchum
describes





"David" wrote in message
oups.com...
Hey All,

I have a room I can enter from two different doors. Each has a rocker
type switch on the wall. The lights are flouresant tubes. Suddenly
one of the switches needed to always be in the down position in order
for the lights to have a chance of going on while using the other
switch. If this particular switch was not in the down position, then
the lights would always be off no matter what I do to the other
switch. I went to Home Depot and changed out both switches. It
fixed the problem completely for about 2-3 days.. Suddenly the same
problem is occurring again (now with the new rocker 3-way switches).
How could this be? Anyone have any idea what is going on here and
how to fix this problem?

Thanks a bunch for the help!

-David