If I had to hazard a guess based upon what you are telling me, I'd say the
bulb that the "non functioning" timer is controlling is burned out. Two wire
electronic time switches require a trickle of current to flow through the
lamp or lamps that they control to function. If you put your bulb tester
across the two wires that the switch was connected to and got no light,
you've either got an open circuit or a blown bulb. I'm guessing the bulb



"FLHTPI" wrote in message
...

Some years ago, I installed two automatic timer switches next to each
other. They have built-in digital timers to automatically shut off
the two outside lights. They work great, although every four or
five years, I have to replace them, because something in the switch
breaks. They're not expensive, and it's no big deal.

Last Summer, I replaced them with two somewhat more expensive switches
which I bought at the electrical supply store. As usual, they worked
fine. Until recently. One of the switches just stopped working.
There was no digital display, no nothing. I assumed it was a bad
switch that had died prematurely.
This afternoon, I removed it and was about to head down to the
electrical supply store to replace it, and I thought, just to be sure,
let me check the wiring, to make sure that's not the problem.

Here's what I have:

Two separate sets of wires come of the box. The switch that stopped
working was wired the same as I've had them both wired for years: The
black and white go to the two wires on the switch. The switch next to
it, (the one that's functioning), is wired to it's two wires, black
and white, exactly the same.

When I take my light bulb/circuit tester, here's what I find:

When I connect the two wires that were connected to the
non-functioning switch, nothing happens.
When I connect the two wires connected to the functioning switch, the
bulb on the tester lights, (as I expected).

Now, back to the wires from the NON-functioning switch:
When I connect the hot wire to one end of the tester, and touch the
other lead to the box, it lights.
When I connect the hot wire from the non-functioning switch to the
ground on the other switch, it lights.
When I connect the hot wire to from the functioning switch to the
ground on the non-functioning switch, it does NOT light.

My conclusion is that something has changed with the ground side of
the wiring that was connected to the non-functioning switch.

These wires have been in place for years, since before I bought my
house. They've never been moved or touched. All of a sudden, I'm
seeing this change.

I checked the breaker panel, and of course, the connection there seems
to be fine.

Any helpful input or thoughts are definitely needed here.

Thanks in advance!