I have two 50 amp fuses that bring power from the main shutoff to my garage. When I flip the breaker in the garage all my readings seem to be normal. As I begin to turn just the lights on after I get just 3 or 4 (60 watt simple everyday led light bulbs) turned on the lights begin to dim. (The breaker box has 8 25 amp breakers in it and uses all 8 breakers for the outlets and the lights). If I have only one light on and I attempt to plug in anything into an outlet the single light I have on will lose over half of its brightness.

No matter which light I have on the above problem seems to occur. Why would it do that?

  • Is this an attached or a detached garage? What make and model is the breaker panel? What gauge are the wires in the walls? Mar 3, 2020 at 12:41
  • 2
    Sounds sort of like a "lost neutral" problem (put that in the search box to see what I'm talking about). Picture of panel and of the 50 A fuses/shutoff would be helpful. If you have a multimeter, check voltage at outlets before & after dimming and report the results. Mar 3, 2020 at 15:02
  • We’re backstabs used? Bad connections can cause a voltage drop, LED lighting that is dim-able are very sensitive to voltage variations.
    – Ed Beal
    Mar 3, 2020 at 15:20
  • Yes, can you give us voltage readings as this is happening? Mar 4, 2020 at 1:07

1 Answer 1


You've lost a wire in your feeder - probably a neutral

And this should be treated like an emergency. If it was your whole house, we'd be telling you to call the power company ASAP.

If it's a lost neutral, the problem is that while half your circuits' voltages are going down, the other half are going up - and lighting a 120V appliance up at 190V is a good way to start a fire. Also, if your main-subpanel connection is the obsolete 3-wire type, a lost neutral is energizing all your grounds and putting lethal voltage on precisely the things that are presumed to be safe.

Fortunately there are only a few places where this problem could happen; the neutral bar in either panel, or the places the hot wires terminate in either panel. There's also a possibility of wire/cable damage, but that generally happens right after construction of some kind.

If you have a 3-wire connection (hot-hot-neutral-NO GROUND) this is a very dangerous situation, because as goes the neutral, so goes the ground.

  • Hope so - the OP didn't indicate the age of the feeder. If it's ancient, it might not be even in a conduit & there could be decay & breakage almost anywhere. Mar 3, 2020 at 19:59
  • Not gonna copy-paste the rest of the answer?
    – user253751
    Mar 4, 2020 at 13:11
  • @user253751 I don't know what that means. If you think it's a dup, then VTC the question as dup, but the "lost a neutral on a subpanel" seems new. Mar 4, 2020 at 14:04
  • 2
    @Harper-ReinstateMonica You are the official Lost Neutral Person of DIY Stack Exchange. I expect a lot more text in your Lost Neutral Answers.
    – user253751
    Mar 4, 2020 at 14:51
  • @user253751 good point, I'm not giving lost neutral the attention it deserves. Edited. Mar 4, 2020 at 15:59

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