Wacky Voltage Problem


Old 07-22-09, 08:28 AM
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Wacky Voltage Problem

Trying to help a friend with an interesting problem. She lives in an old house in St Petersburg, FL, with a relatively modern circuit breaker panel. About a week ago, ceiling light fixtures in 4 rooms stopped working. I assumed it was simply the circuit breaker, but it turned out that is not the problem.

Here is what I do know:

The ceiling lights were working until recently.

Output from circuit breaker is 110v as expected

I checked the voltage at eack of the wall switches that control the ceiling lights, and the voltage at the four switches ranges from 7 to 13 volts.

I am guessing there is a single cable with a pigtail to each wall switch.

At each wall switch box there are two paper insulated wires tied to the switch. There is no ground wire or any other wires in the light switch box.

What is the likely cause of this low voltage problem?
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Old 07-22-09, 08:45 AM
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Voltage checks at the switch usually don't mean much. If you were using a digital meter nothing. Since only two wires at the switch the power almost certainly comes in at the fan. At the fan is where you need to check. Most likely a loose wire nut connection.
Old 07-22-09, 09:04 AM
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I'd identify everything on that one circuit. And if outlets are also on it, I'd check outlets as well, for loose connection and/or for backstab connections.- since the (bad)outlet may then be feeding those ceiling boxes.

Also make sure that all the wire connections, including neutral, for this circuit, are tight in the panel box on both the breaker and the neutral buss.
Old 07-22-09, 07:02 PM
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check 1st box in run

i'ld check the first ceiling box in the first room of the four rooms, i'ld suspect a loose wire nut on either the hot or the nuetral, and would also check the nuetral at the bus. you don't have aluminum wiring do you?
Old 07-22-09, 08:56 PM
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I think 7 to 13 volts probably means 0 volts. Its being generous. There is no power there. You have a bad connection somewhere on the circuit.
Old 07-23-09, 08:05 AM
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I think kd went to the beach. . It be fun to learn where the problem was.

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