Welcome to the DoItYourself Forums!

To post questions, help other DIYers and reduce advertising (like the one on your left), join our DIY community. It's free!

Grinding noise when switch turned on


shalihe74's Avatar
Member

Join Date: Jan 2010
Posts: 106
AZ

08-03-17, 10:56 AM   #1 (permalink)  
Grinding noise when switch turned on

Hi all,

Been a looooooong time since I've had to post up a question here. I think this is a good one, though.

I have an outdoor light that, since 2011? 2012?, has been on an X-10 switch (i.e. old school home automation). It's switch loop wiring, so no neutral. Until a couple weeks ago, it has worked flawlessly. A few weeks back, I noticed the light wasn't coming on anymore. Bulbs were good. Switch registered receiving the signal - it just didn't come on. Having had a couple of these X10 switches fail, I figured that it was just this one's time, and put in a modern switch.

As soon as I turned on the switch, the back light came on... then, with an impressive POP, out it went. Yikes #1. My volt sensing device told me that current was flowing through the switch, even as I tried to toggle it on/off. So apparently whatever blew out the bulb also blew out the switch. (Yikes #2.)

I've had THAT happen, too, with this brand, so grabbed a normal, non-automated switch and installed that. When I turned that one on, there was a GRINDING noise. Not a buzz, but a loud grinding... like a small garbage disposal in the wall. BIG Yikes #3. At that point, I took out the switch, capped the wires, tucked them safely out of the way, and came looking for expert help. Here I am.

I'm >guessing< that the wiring into the light fixture has, over time, gotten loose or dirty or something. But...the grinding noise is disconcerting enough, that I'd like to hear what folks think it might be before I start poking around some more.

Thanks so much in advance.
-Shauna

 
Sponsored Links
Zorfdt's Avatar
Forum Topic Moderator

Join Date: Sep 2005
Posts: 3,743
PA

08-03-17, 11:22 AM   #2 (permalink)  
I've seen my share of blown "smart" switches, but I've never seen a standard toggle switch damaged beyond usability by a short or surge.

My guess is you've ended up with a direct short somewhere in your switch change. The grinding is probably a slightly loose connection arcing.


Good luck... what's the worst that can happen?

 
shalihe74's Avatar
Member

Join Date: Jan 2010
Posts: 106
AZ

08-03-17, 11:52 AM   #3 (permalink)  
The normal toggle switch didn't fail; it did a splendid job of turning off when I heard the grinding noise. Thankfully. It's a long dash from that room to the breaker box.

Thanks for the confirmation that something loose somewhere is probably causing the sound & problem. This fixture is one of the few I haven't had to doink with in the past 8yrs; considering the quality of the workmanship on the others, it is overdue for something to go wrong with it.

 
PJmax's Avatar
Group Moderator

Join Date: Oct 2012
Posts: 38,080
NJ

08-03-17, 04:05 PM   #4 (permalink)  
Usually with a direct short.... the breaker would (or should) trip. The noise could be the current flowing thru the wires. That circuit could be over fused too. Meaning too large a breaker for the size of the wire. Time to break out the ohmmeter.


A quick little story. A good friend of mine opened a string of temporary holiday stores every year. He'd go into 10-12 malls on a several month lease. I'd do all the wiring. You want to see the worlds worst wiring. Just incredible. The panels were always in the back of the stores and all the circuits requiring work were all the way in the front. Panels were never labeled. I had a pair of pliers that were strictly for "remotely shutting off the power". The last circuit I shut down was a #12 cable connected into a 40A heating unit. Wow... that was exciting.


~ Pete ~

 
Tolyn Ironhand's Avatar
Group Moderator

Join Date: Nov 2007
Posts: 11,352
MN

08-03-17, 06:43 PM   #5 (permalink)  
As PJ alluded to, if there is a lot of current flowing through some wires, like a short, the wires will hum and dance inside conduit. That might be what you heard. However, most cases if it is a short it will trip the breaker quickly.


Electrical AC/DC and lighting Moderator
Professional Electrician, Handyman, all around swell guy!
40,000 people die in auto accidents per year in the US. We should ban cars.

 
ray2047's Avatar
Group Moderator

Join Date: Mar 2006
Posts: 32,011
TX

08-03-17, 06:50 PM   #6 (permalink)  
My volt sensing device told me that current was flowing
If you mean a non contact t tester there is a fifty fifty chance it was lying to you. They are useless for accurately determining if you have real voltage.
apparently whatever blew out the bulb also blew out the switch
If it blew out the switch no current would flow. I suppose it could have fused the contacts but that seems unlikely.

Do you have a Zinsco or FPE panel?


I can explain it to you, but I can't understand it for you.

 
shalihe74's Avatar
Member

Join Date: Jan 2010
Posts: 106
AZ

08-12-17, 01:32 PM   #7 (permalink)  
Sorry to disappear without responding to y'all! (I know you were all waiting with bated breath for a reply.) Trying to get this light working was the last thing on my to-do list before ducking out for a long weekend. I got back to it today.

Took the fixture down and (amazingly) it was wired up correctly. Something in the fixture itself (or in the light bulb?) went bad. The last bulb that blew, charred its socket when it went. I tested each section of the circuit as I reconnected everything, and it all seems fine now that the fixture is gone. So I have 6 new fixtures on their way and will be spending next weekend replacing all my outdoor lighting. Kind of excited about that, actually.

This is what I have as a volt sensing device. If they're known for being dodgy, I need to buy a lottery ticket, because mine has worked amazingly for 9 years. Saved my butt one time when a circuit breaker went bad: I had turned it off to work on some stuff, but power was still flowing when I checked. I love this thing.

I honestly can't say for certain whether I have a Zinsco or FPE box, BUT... I did have a real electrician out a few years ago to do a couple jobs I didn't know how to or wasn't comfortable doing (showing me how to replace the aforementioned bad breaker and getting the right gauge cable running to an AC unit) and he didn't mention that I had a breaker box of doom. I'll double check when I head back outside next weekend.

40A on 12AWG?! WOW!!! When I first moved in here, I found a lot of circuits with 20A breakers and 14AWG cable, and I >think< my 50A AC had... 10? before we changed it to 6. But that's about as bad as that got. My favorite WTF wiring in my house was a cable that started as 12 on one side of the kitchen then mysteriously switched to 14 before the last two outlets. It took me 4 years of periodic poking around before I finally found the junction box closed up in the wall behind a cabinet where the change happened.

... Although, thinking about it, the metal junction box the previous owners just buried was a fun one, too. Which you all (PJ, Ray) helped me with, now that I think about it.

As always, thanks so much!! You guys are awesome.

 
PJmax's Avatar
Group Moderator

Join Date: Oct 2012
Posts: 38,080
NJ

08-12-17, 01:49 PM   #8 (permalink)  
Thanks for stopping back and letting us know how you made out.


A non contact pen tester like that is good for one thing.... letting you know there is dangerous voltage in the area. Unfortunately it's of no use in repairing shorted circuits or circuits with a neutral problem. It also cannot confirm that you actually have the full 120v at the test point.


~ Pete ~

 
pugsl's Avatar
Forum Topic Moderator

Join Date: Mar 2008
Posts: 7,141
NC

08-12-17, 02:13 PM   #9 (permalink)  
Only thing I used a non contact tester for was dryer repair. I could tell if both lags had power at plug. Quick check before got meter out to confirm.

 
shalihe74's Avatar
Member

Join Date: Jan 2010
Posts: 106
AZ

08-13-17, 12:03 PM   #10 (permalink)  
Aaaahhh, I can see how you pros wouldn't see tremendous value in the volt sensor. As a troubleshooting device, it doesn't have a lot to offer. Power yes? No? Though I do have a multimeter (that I use when working on my motorcycles), the volt sensing device is all I've ever needed in the house - the ability to know the power is on/off in a cable before messing with it, and to find out where along a circuit power stopped flowing/where to start troubleshooting. Honestly, if I ever came across a problem more complex than that (i.e. if taking the fixture off the circuit hadn't resolved the weird grinding noise), I'd call in my pro. I know my limits!

 
Search this Thread