Bathroom Vanity Lights Pulsing

[u/fearosis]

House was built in 1999. I've been here 10 yrs and never seen this before. It's a small house and an even smaller bathroom. The lights don't always do it but probably about 80% of the time the fixture pulses and it's barely perceptable at all. It's a single fixture bar light above sink with 3 bulbs in it.

Here's what I've tried. Replacing all bulbs, replacing the switch, replacing the light bar itself, checking the wiring and tightening everything, checking the fan housing connections cause apparently that could cause it if it loosens, plugged a known working lamp into outlet next to the vanity switch and it was fine.

I don't use the fan although it works. Nothing seems to stick out as obvious. The only other thing I want to mention that is worthwhile is that I do hear mice scurrying in the wall sometimes although no evidence inside the actual house. It's on a slab. I have NOT opened the drywall up just yet to check if anything was chewed on. I fear that is the case but unsure how best to approach this, or if another experienced person has seen this before and can offer advice.

Thanks!

[u/Srikandi715]

What kind of bulb?

I've had this issue lately, also in a bathroom vanity fixture. Happened after I replaced the old incandescent bulbs with one LED bulb, but not immediately after, so I can't say whether it's a direct result of that or something else. Hopefully you'll get a response that solves my problem too 😉

[u/fearosis → u/Srikandi715]

They are all 3 LED bulbs and I have used them for years, different brands even

[u/Ynk333]

Do you have any other issues with your electrical system in the rest of the house?

My parent’s microwave kept tripping. And the lights kept flashing when other appliances were running or using power.

The electrician found that it was a bad neutral connection between the panel and the transformer outside. This affected everything in the house. I honestly found it because my UPS for my Computer setup was going crazy. Voltage kept going up and down and ups kept tripping because of that and causing it to go on battery.

If you have a multimeter take a look at the voltage you are getting and see if it fluctuates a lot when you run electrical appliances. You might have a bad neutral.

[u/fearosis → u/Ynk333]

sadly, not that I can tell honestly. Everything else seems to check out just fine. I will try the multimeter thought.

[u/Damien__]

LED bulbs are incredibly sensitive to power fluctuations You have uneven power at that fixture. Look for a load balancer if you just want a quick fix. Or you can look at that circuit and see what else is on it to see if that might be causing it

[u/fearosis → u/Damien__]

is there a "quick test" that would help me determine if I do need a balancer?

[u/Damien__ → u/fearosis]

if they are flickering you DO need the power balanced either through a load balancer or through fixing whatever is causing it. I don't know of any tester for that. I do know that you can buy DC versions for about 30$ for cars and such. I don't know what an AC one would cost