How do I detect and repair faulty wiring?

Question

Recently, during a storm, an outdoor spotlight was broken in its socket, its internal wiring shorting out. The lights happen to be on a motion sensor, and in turn on switch, and a breaker at the panel.

Replacing the spotlight bulb, nothing worked, so I checked with a non-contact tester, no power in the socket. No breakers were tripped at the panel. So I pulled the switch; it looks like there is no power their, either! It seems like everything else that should have power does, but I haven't exhaustively checked every nearby outlet.

This is in Canada, and I know the house was just about entirely rewired ~10 years ago.

I'm at a loss how this is possible, but anyway. How can I find the fault?

Answer 1

Use your non contact tester, and start tracing the circuit back to the panel. Check each device along the way, and keep a close eye out for GFCI receptacles that have been tripped.

You may want to pick up a multimeter, and test for voltage at the switch, and at the fixture. Water could have entered the fixture housing, and fried the motion sensor. So make sure you check the wires feeding the fixture.

If you don't feel comfortable working on live lines, call in a licensed electrician to have a look.