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DC switch mystery

March 14, 2021, 06:25:47 pm

Project One: [Context of the problem]...is to replace fluorescent lights with LED. Bedroom lights. Four switch panel disconnected from wall but not from wiring. I have lost power to/from left switch (driver's side bedroom under-cabinet lights). I am trying to trace the 'flow' into and out of the switch and then trace out to find where I have a disconnect.
Problem Two: The second switch (passenger-side under-cabinet lights) works. The lights still work, BUT the mystery is multiplied when I use the voltmeter to check connections to the switch.
(1) When the switch is on and therefore the lights are on...the voltmeter shows ZERO DCV current.
(2) When the switch is 'off' and lights are therefore off, using the voltmeter, I get 13DCV.!!!!
Logically I should have the opposite happening!
Ideas??

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Re: DC switch mystery

Reply #1 – March 14, 2021, 08:02:35 pm

You need to connect 1 side to a good  ground  and other to the switch    if you are putting one lead to each side of the switch, you will get theses readings.

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Re: DC switch mystery

Reply #2 – March 14, 2021, 11:09:26 pm

Woody I had read a really easy tool to build that really works well. It is a extension cord with both the neutral  and power disconnected leaving you with just the ground pin. This and your meter or test light work very well. Gives you known good ground when ever you need one. Wasn't my idea, but it's a handy tool.
Scott

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Re: DC switch mystery

Reply #3 – March 16, 2021, 03:39:54 pm

Thank you both. That is very helpful.

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