Tonight I went over to my wife’s best friend’s house because a bunch of their outlets and lights stopped working yesterday. It didn’t trip a circuit breaker, it just stopped working, but there were a couple of times where it worked for a few minutes and then went off again. Now it’s just off. This suggests that there is a loose or broken wire. If there were a short, it would trip the breaker.

This house is not quite traditional – it’s a double-wide trailer dropped onto a foundation. The parts of the house that don’t work are pretty much everything on one side, both front and back. The outlets and lights on one wall of the master bedroom and everything in the master closet are out, but the rest of the master bedroom works.

I checked the voltage on each of the circuit breaker outputs and found that they are all 120 volts. After ensuring that all the connections in the box were tight, I tried to trace the wiring into the crawlspace, but found that it was all hidden from view behind particleboard.

I discovered something very curious when I started turning off breakers. Breaker number 1 is labeled as side A and B in the rear of the house, which would include the master bedroom, the master closet, and at least one of the other two bedrooms. Breaker number 2 is labeled as being one side of the front. Breaker 3 is the other side of the front.

When I turn off breaker 3, the lights in the front on the same side as the breaker box all go out, which was expected. If I turn off breaker number 2, nothing happens, which fits the symptoms. The strange thing is with breaker 1. If I turn only that one off, the lights in the rear of the trailer on the same side as the breaker box dim a little bit and start flickering very slightly. It’s only when I switch off both number 1 and number 2 that the lights actually turn off.

This means that the two circuits are connected together somewhere in the house. The slight dim and flicker would indicate that the bridge is not solid. Although it’s possible that they are connected together by something that’s plugged in somewhere, it’s more likely that both circuits were wired to the same electrical outlet or light switch. My instincts tell me it’s not likely that the outage and the bridge are the same problem.

Fixing the problem is going to cause a lot of disruption in their lives, whether they hire an electrician or I help them with it. I believe that if they move things out of the way of all their outlets, I can find the bridge with my multimeter and remove it. If there is a loose/broken wire, it will probably turn up during the survey. I really hope I don’t have to start pulling the boards covering the wiring in the crawlspace or the wood paneling in the living areas.