As I was getting a property ready for inspection, I had to take care of some electrical issues. All of them were trivial, except one. In the end, I had one last dead electrical outlet to figure out.
All of the advice I found online said to call a professional. All of it. Here’s the exception, and here’s how I found it.
The first thing I did was to inspect the outlet itself. The wiring on it was sloppy, and my standards aren’t high. The wires weren’t looped around the screws. So I looped them, then tightened the screws a good three-quarters of a turn, then replaced the outlet. No difference.
The other easy explanation is a bad outlet. Sometimes outlets just go bad, and this one had clearly endured some abuse in its day. Maybe its time had coincidentally come while I was doing the other work? It didn’t make any sense, but it sounded possible. So I replaced it with a new outlet. No difference.
Then I checked the other outlets on the same circuit. A tripped GFCI upstream from an outlet can make it go dead. That’s by design. And, thankfully, before I started work, I mapped out every outlet and wrote down what circuit breaker controlled it on a piece of tape and stuck it to the outlet. So I knew exactly which outlets to check to see if they were upstream of it. None were, as it turned out. But at least I knew.
So then I pulled out my multimeter, and I found something really odd. When I removed the outlet–carefully!–and–carefully!–applied the lead from the multimeter to each wire–did I mention you should do this carefully?–I didn’t get zero. It would initially register at something less than 1 volt, then slowly drop down to zero or nearly zero over the course of a second or two or three. That’s not what I would expect a dead outlet to do. I would expect a dead outlet to be dead zero, period.
I puzzled over that for a good 24 hours when I remembered something.
This outlet is underneath the front window. There are two light switches by the front door. One controls the outside front light. The other does not control the light in the room. (That switch is on the other side of the room.) And then I remembered the funky wiring on the outlet, with three wires going to it and one empty screw, which in my limited experience often indicates a light switch is involved. And a light switch would explain the very small amount of current leaking through for my multimeter to pick up.
The only logical thing for that switch to control is that suddenly dead electrical outlet.
So the first thing I did after work was to plug a lamp into the dead outlet, flip both switches by the front door, and–thankfully–see light. From the lamp.
That switch controls the outlet, and I’d forgotten to check or note it earlier. I’m glad I figured it out before I managed to track down an electrician.
So my advice–which will be painfully obvious to some people but not everyone–is that if you have a dead electrical outlet that you can’t figure out, before you start tearing into the outlet, turn on every light switch in the house and see if it comes back. Then use the process of elimination to figure out which switch is controlling that light.