MJR wrote:
symptoms
1. garage lights won't turn on
2. garage door opener won't go up/down
3. when light switch is off, garage opener
sensors light
up 4. when light switch is on (lights don't go
on), sensors
go off 5. Voltage tester shows 104 volts in all
outlets in
garage what should I do (besides calling an
electrician)?

the problem began soon after the first rains in
6 weeks

the power to the garage is underground conduit
from the
house, under the yard to the garage.

Hi,
Using analog meter like Simpson 260? Measured
voltage
between hot and neutral, hot and ground? Is it
on GFCI
circuit?

That sure sounds like an underground wiring
problem. Not wires shorted to each other, but
shorted to earth ground.
1. Try killing ALL power in the garage:
physically unplug as much as you can, if it can't
be unplugged, be sure it's OFF and not drawing any
power (as in standby modes).

2. Do you see something closer to 110V at the
panel in the garage? If so, something is drawing
power between that panel and the main panel - as
in, a ckt to gnd due to insulation compromise,
whatever.

3. IF you're seeing something closer to 110Vac,
then connect something in the garage that draws
power. Perhaps a halogen light, or anything that
will draw a few amps. Look at that same voltage
again. If it's dropped substantially from
whatever voltage you read before, it's definitely
going to be an underground wiring problem,
probably due to the water you mentioned.

4. IF the voltage in step 1 is 104V regardless of
whether anything is connected or not, go to the
main panel and read the voltage to the garage
wires there.

5. IF it's 110V, then there's something drawing a
lot of current underground.

6. IF it's 104, something else is going on and
it's not underground, most likely. To be certain,
just pull the wires from the main panel connection
(panel OFF) and see if that brings it back to 110
or whatever.
Make sure the whole house isn't seeing that low
voltage.

Neglecting meter calibration, parallax error,
etc., 104 V ac at the main panel and thus the
whole house is right at the lower limit of usable
grid voltage. In that case the problem most
likely becomes that of the transformer out on the
pole being bad or needing replacement. 104Vac is
also tough on anything with a motor in it; they
tend to run pretty hot. 110 to 120 V is the
normally accepted norm, depending on where you
live. Tolerance is allowed to be up to 10% but is
seldom that far off for even the most remote
areas.

If I've mistated anything I'm sure someone will
catch it and correct itg.


HTH,

Twayne