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Open circuit has power, close the circuit no power???

3K views 7 replies 4 participants last post by  joed 
#1 ·
A little background: a couple days ago I had a window air conditioner and a treadmill running on 2 different outlets in the same circuit. After a 10 minutes or so, they both went off for a couple seconds then both came back on but something started to smell so I turned both off. Several hours later I tried turning the air conditioner back on and it worked for several seconds before turning off. Then I tested the rest of the circuit and found that none of the outlets were working but the circuit breaker was still on for the circuit. We thought maybe the outlets had been broken/short-circuited somehow so we replaced them and in the process figured out that the outlet would have power as long as the wires going away from them weren't connected to anything.

So right now I have a first outlet that connects to a 2nd outlet that connects to a ceiling fan and the 2nd outlet also goes onto a 3rd outlet that also has a switch that goes to a ceiling light. Right now the wires from the switch go to the ceiling light area but are not connected to anything and the other wires from the 2nd outlet go to the ceiling fan area but are not connected to the fan. With the circuit on like this, the 3 outlets work and the loose wires at the ceiling light area (with switch on) and at the ceiling fan area say they have power using a light-up circuit tester. But when we connect the ceiling fan to the wires then the ceiling fan doesn't work and nothing else in the circuit works. What's wrong?
 
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#5 ·
That is exactly what I suspect is happening. You have a high resistance connection and as soon as you put any load on it, it measures open. Those light up tester do not draw any current and can easily get fooled.
The ceiling light is applying a load. I suspect if you apply the load to another part of the circuit you will have the same results. This is a very common problem if your receptacles use the pushin back stab connections. The wire connection should be on the screws.
 
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