3-way receptacle tester light pulsating

1958 home GA. Modern panel (1990’s?). The home had a mixture of 2 prong ungrounded receptacles, 3 prong ungrounded receptacles and three prong grounded receptacles. The home had a handful of visible electrical deficiencies (DIY type crap etc.) Panel cover was obstructed and I was unable to remove it. Also, there was no visible ground to be found. No ufer. No ground rods.

One thing I have never seen. I plugged in the 3 light tester and of the yellow lights would brighten then dim. Interestingly, the pulsing was rhythmic. One second bright, one second dim.

Any ideas what would cause this and is it an indicator of something more complex?

Just my WAG… Neutral being used for the ground in the entire home.

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The pulsing was observed at one outlet only. With all the other problems, do you think this observation is report worthy? Do you think it will it help the client or electrician?

Yes, as it may help diagnose. Suspect a bootleg ground, thus the neutral pulse (if that’s an actual thing. I dunno).

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Agreed, I will throw it in my list of observations without making a diagnosis. I will let the electrician regard or disregard as he sees fit. Thanks!

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@bcawhern1 did you make a video of this? That would be interesting to see, not to mention learning what would cause it. :thinking::thinking::thinking:

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No video. Sorry. Now in retrospect, I wish I had.

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15 Lighting circuit.
1: Was that outlet controlled by the light switch?
2: If so, was the switch a dimmer switch?
3: Was there Led lighting?

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Good questions Robert. No dimmers or LEDS.

I had a fixture that had all regular bulbs in it except one led, because a regular bulb burned out. The 3-way switches were regular 3-way switches. When I turned on the light fixture, 4 regular bulbs came on as normal but the led pulsated until I replaced it with a regular bulb that I found in my shop.

I don’t know if that is helpful or not.

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Brian, sometimes when Three Bulb Tester contact prongs contact Loose or worn Outlets blades flickering may occur. Current is being impeded downstream.
I always tried 'several different outlet testers, I still carry 4, and lastly, a non contact current detector in every opening when readings are skewed.

I personally would refer outlet test flicking to a licensed electrical contractor for that specific anomaly.

Have a great day.
Robert

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JJ’s on to something…prolly lmgtfy ;~}

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I’ve had my tester do that as well. Plug it in to the other outlet on the same receptacle and it’s fine. Usually they are a bit looser feeling too so I write them up as old and worn - in need of replacement. Once it’s pulled, replaced, wrapped with tape and secured it should be fine. Unless it’s a nail through a wire, then you won’t see it anyway. But you’re there and inspecting it, so it hasn’t burnt down yet.

We can only go so deep. The deeper you delve, the deeper the hole you can unintentionally dig for yourself should problems arise. Find a good balance and you’ll be fine. Stick to the standards.

Yes, I have observed plenty of flickering receptacles. However, this was a pulse. Almost like a leg of a phase. I do not think this was a loose connection type issue, but I could be wrong. I may never know. I have a feeling once the electrician addresses all the other issues, it will be resolved.

A more feature rich circuit analyzer may be a fun tool to keep around.

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Whats the question. Report what you see … Refer to an electrician and move on

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I agree with Dan. Sometimes we, myself included, get wrapped up in trying to dive too dep into root causes. 9 times out of 10, the client does not care what the root cause is. They just want to know that an issue exists and that someone who specializes in that type of issue needs to get involved.

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Low voltage can cause pulsing lights. That is why I measure outlet for Vd/Voltage drop. Not the best article but it gets the point across, I hope.

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That is what I did…good advice, Dan.

It depends… Was the writer trying to figure out what was wrong so he could determine whether it was of significance to require further investigation, or was he trying to understand why something does what it is doing in order to grow in personal/professional knowledge? Whether it changes the narrative or not, learning/understanding the ‘why’, helps us grow personally and professionally. Now… your point is quite valid if/when the narrative is used to try and explain the ‘why’… which happens all too often, when some want to show how smart they are.

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