# Replacing an outdoor light fixture **URL:** \ **Category:** Factual Questions\ **Created:** [May 5, 2007, 4:23pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897 "2007-05-05T16:23:24Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 5, 2007, 4:23pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/1 "2007-05-05T16:23:24Z")
The motion detector on my outside floods (on the porch, mounted on the porch ceiling) has died. I want to replace the fixture but haven’t done anything like this before. Am I correct in thinking this is what you do? - Turn off switch and breaker to fixture - Unscrew fixture - Somewhere in here you can test with those little testers you just put near the wire, right? - Disconnect old fixture - Connect new fixture in same configuration Am I not understanding anything here? It seems pretty simple - I just want the same thing, a two floodlight motion and light detector outdoor light. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 5, 2007, 4:53pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/2 "2007-05-05T16:53:35Z")
That’s the basic idea, but I would suggest you have someone who’s done it before come and walk you though it. Like I said, you’ve got the idea down, but saying things like “Somewhere in here you can test with those little testers you just put near the wire, right?”\* make me nervous. Someone to watch over your shoulder will be helpful in making sure you don’t kill yourself. Those little testers don’t go _near_ the wires, they go on the wires, and you have to make sure you test all the wires in the box becuase there may still be hot ones and you want to know which ones to stay away from. ---
**Author:** ![Zsofia](https://avatars.discourse-cdn.com/v4/letter/z/7bcc69/32.png) [@Zsofia](https://boards.straightdope.com/u/Zsofia)\ **Post date:** [May 5, 2007, 5:17pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/3 "2007-05-05T17:17:10Z")
I thought they had them now where you could just hold it near? I know about the kind where you put the probes to them. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 5, 2007, 5:23pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/4 "2007-05-05T17:23:15Z")
[QUOTE=Zsofia] I thought they had them now where you could just hold it near? I know about the kind where you put the probes to them. [/QUOTE] I’ve never seen exactly what you’ve talked about. They do have clamp ones, but that’s not what you would want for this. You just need a cheapo voltage tester, the kind with the two wires and the light on it. But remember, when you use them outside in the sun it’s can be really hard to tell if the light is on or not. ---
**Author:** ![Queen\_Tonya](https://avatars.discourse-cdn.com/v4/letter/q/4491bb/32.png) [@Queen\_Tonya](https://boards.straightdope.com/u/Queen_Tonya)\ **Post date:** [May 5, 2007, 5:27pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/5 "2007-05-05T17:27:22Z")
There are indeed proximity voltage detectors that light _and_ beep when held near live circuits. I’ve got a Greenlee one I think was maybe 12 bucks. Available at your local hardware store for sure. The issue to be wary of, though, is that if you detect anything by poking it into and around the area, you won’t know what’s hot and what’s not, like **Joey P** is worried about. At that point, stop and make sure you’ve got the right breaker off, and if you still get some voltage detected, either you’ve got mislabeled breakers or a problem requiring more experienced assistance. So get your prox detector and go for it, just be sure to test your tester on a known live circuit first to be sure it’s working properly! ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [May 5, 2007, 6:11pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/6 "2007-05-05T18:11:26Z")
I always reccommend [this book](http://www.amazon.com/Complete-Guide-Home-Wiring/dp/1589232135/ref=pd_bbs_sr_2/002-9081725-4458465?ie=UTF8&s=books&qid=1178387995&sr=1-2) to anyone who shows any interest in doing their own electrical work at home. It covers pretty much everything, and does it well. The proximity readers work okay to see it you do have power for troubleshooting, but I wouldn’t use one to see if the circuit is safe. Use a contact tester for that. The book shows you how to safely test circuits. You can do it. 🙂 Next thing, you’ll be installing a ceiling fan. Peace, mangeorge ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 5, 2007, 7:14pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/7 "2007-05-05T19:14:42Z")
[QUOTE=Queen Tonya] The issue to be wary of, though, is that if you detect anything by poking it into and around the area, you won’t know what’s hot and what’s not, like **Joey P** is worried about. At that point, stop and make sure you’ve got the right breaker off, and if you still get some voltage detected, either you’ve got mislabeled breakers or a problem requiring more experienced assistance. [/QUOTE] I’ve never used a proximity detector, and I can’t say I would trust one (although I do like Greenlee as a brand), I feel better actually applying the voltage (or lack thereof) to the tester itself. Again, having not used these, do they need to have a complete circuit to work? If I have a wire sticking out of a box with nothing attached to it, will it tell me if it’s live or not? What happens if there are other live wires running though the box, will that cause a false positive? My reason for being worried as that even though the OP has the general idea as to how to do this, if you don’t know how to use a multimeter/voltage tester, you really sould have someone walk you though it a few times until you get the hang of it. ---
**Author:** ![KneadToKnow](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/kneadtoknow/32/3999_2.png) [@KneadToKnow](https://boards.straightdope.com/u/KneadToKnow)\ **Post date:** [May 5, 2007, 7:23pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/8 "2007-05-05T19:23:22Z")
**Zsofia** , I’ve done what you’re talking about doing, and yes, it pretty much is that simple. I’m sure you have an idea of where to locate a good DIY manual on home electrical work. 🙂 Oh, and just be warned: You may technically be violating zoning laws by doing this yourself. No kidding. I am told that here in Charlotte, the letter of the law requires pulling a permit (which means being a licensed electrician) and getting an inspection for changing a light fixture. ---
**Author:** ![Queen\_Tonya](https://avatars.discourse-cdn.com/v4/letter/q/4491bb/32.png) [@Queen\_Tonya](https://boards.straightdope.com/u/Queen_Tonya)\ **Post date:** [May 5, 2007, 7:36pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/9 "2007-05-05T19:36:37Z")
[QUOTE=Joey P] I’ve never used a proximity detector, and I can’t say I would trust one (although I do like Greenlee as a brand), I feel better actually applying the voltage (or lack thereof) to the tester itself. Again, having not used these, do they need to have a complete circuit to work? If I have a wire sticking out of a box with nothing attached to it, will it tell me if it’s live or not? What happens if there are other live wires running though the box, will that cause a false positive? My reason for being worried as that even though the OP has the general idea as to how to do this, if you don’t know how to use a multimeter/voltage tester, you really sould have someone walk you though it a few times until you get the hang of it. [/QUOTE] Any place voltage is present, they’ll pick it up and beep. A single wire sticking out, yes it’ll beep if it’s live. The problem of other wires running through was exactly what I was worried about and said might require more experienced assistance. A multimeter with probes is a better bet, absolutely, but lacking someone to walk them thru it, a prox detector isn’t a bad way to go either. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [May 5, 2007, 8:14pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/10 "2007-05-05T20:14:54Z")
If you have any doubts what so ever about the presence of voltage in the box, turn off all the breakers in the box. That way you know the circuit is dead. It is way easier to reset clocks than it is to pick your ass up off the pavement after being shocked off the ladder. When you wire the new unit, it will either have a white wire, or a silver screw. The white wire in the box goes to this wire/screw. The green wire/screw gets the green wire (ground) The gold screw/ black wire gets the other wire (probably black or red) If the box is wired with wire nuts (little yellow cap looking things) after twisting them on tightly tug on each wire and make sure it is secure inside the wire nut. ---
**Author:** ![Quiddity\_Glomfuster](https://avatars.discourse-cdn.com/v4/letter/q/c4cdca/32.png) [@Quiddity\_Glomfuster](https://boards.straightdope.com/u/Quiddity_Glomfuster)\ **Post date:** [May 5, 2007, 8:34pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/11 "2007-05-05T20:34:02Z")
Why use a meter? If you flip the breaker and the light goes off, why would there still be voltage? I’ve watched people and helped people change quite a few light fixtures and nobody ever used a meter. ---
**Author:** ![Q.E.D](https://avatars.discourse-cdn.com/v4/letter/q/51bf81/32.png) [@Q.E.D](https://boards.straightdope.com/u/Q.E.D)\ **Post date:** [May 5, 2007, 8:40pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/12 "2007-05-05T20:40:46Z")
[QUOTE=Quiddity Glomfuster] Why use a meter? If you flip the breaker and the light goes off, why would there still be voltage? I’ve watched people and helped people change quite a few light fixtures and nobody ever used a meter. [/QUOTE] You’re trusting that the wiring monkey who installed the circuit did it properly and that you’ve identified the correct circuit breaker to throw. Most likely, it’s now safe. But it’s ALWAYS best practice to check before actually touching the wires. It only takes once. ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [May 5, 2007, 9:05pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/13 "2007-05-05T21:05:30Z")
[QUOTE=Quiddity Glomfuster] Why use a meter? If you flip the breaker and the light goes off, why would there still be voltage? I’ve watched people and helped people change quite a few light fixtures and nobody ever used a meter. [/QUOTE] If the circuit has a shared neutral, you can get the shit shocked out of you this way. Ask me how I know this. ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [May 5, 2007, 11:18pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/14 "2007-05-05T23:18:10Z")
The non contact testers are handy for determining if something is live. I would not trust one to be certain something is dead. A voltage tester with prongs is a bit more reliable but requires you touch them to the conductor. Your project is pretty simple. The wiring might not be exactly the same for the replacement fixture. Be sure to check the wiring diagram that comes with it. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [May 5, 2007, 11:52pm UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/15 "2007-05-05T23:52:19Z")
[QUOTE=Quiddity Glomfuster] Why use a meter? If you flip the breaker and the light goes off, why would there still be voltage? I’ve watched people and helped people change quite a few light fixtures and nobody ever used a meter. [/QUOTE] Zsofia said that the motion detector was dead. It (the detector) could cut power to the light even if voltage is present. Just check it, okay? It’s simple. We don’t to fry our one and only Zsofia. 😉 ---
**Author:** ![thirdname](https://avatars.discourse-cdn.com/v4/letter/t/d07c76/32.png) [@thirdname](https://boards.straightdope.com/u/thirdname)\ **Post date:** [May 6, 2007, 1:08am UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/16 "2007-05-06T01:08:53Z")
I’ve done a couple myself, not having money to hire somebody else; I don’t know if I violated zoning or put myself in danger. I turned off the breaker, I only worked with one wire at a time, and I only used one hand. That way you can’t get an arm-to-arm shock. In both cases they used twisty connectors, where you put the two wire ends next to each other and then twist the cap on. I think I left caps on all wires I easn’t working with at any given time. One gripe I have is that I bought a fixture from Home Depot that looked just like the old one from a distance, but a couple dimensions were slightly smaller, and more importantly the while thing was really light. I think the old one was cast iron, the new one aluminum painted black. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [May 6, 2007, 1:35am UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/17 "2007-05-06T01:35:24Z")
Speaking of those “twisty things” (wire nuts), you need to be sure you get them really tight. About as tight as you can. The wires should be tightly twisted for at least a half inch or so where they come out of the wire nut. They can, and do, come loose. I should mention that I was an electrician for about 30 years. I worked in construction and maintenance, first for a major contractor, then for an oil company (Chevron). ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 6, 2007, 3:16am UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/18 "2007-05-06T03:16:18Z")
[QUOTE=mangeorge] Speaking of those “twisty things” (wire nuts), you need to be sure you get them really tight. About as tight as you can. The wires should be tightly twisted for at least a half inch or so where they come out of the wire nut. They can, and do, come loose. [/QUOTE] But too tight and you’ll break the wires, then you have to restrip them and start over. Remember, each time you do that, the wires get shorter. ---
**Author:** ![mangeorge](https://avatars.discourse-cdn.com/v4/letter/m/d78d45/32.png) [@mangeorge](https://boards.straightdope.com/u/mangeorge)\ **Post date:** [May 6, 2007, 3:27am UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/19 "2007-05-06T03:27:07Z")
[QUOTE=Joey P] But too tight and you’ll break the wires, then you have to restrip them and start over. Remember, each time you do that, the wires get shorter. [/QUOTE] I’ll tell you what I’m going to rmember. I’ll remember that if you break 14 gauge wire, solid or stranded, by twisting on a wore nut, I’ll avoid any contact with you. :eek: And I’ve worked with some pretty rough characters. ---
**Author:** ![Joey\_P](https://avatars.discourse-cdn.com/v4/letter/j/919ad9/32.png) [@Joey\_P](https://boards.straightdope.com/u/Joey_P)\ **Post date:** [May 6, 2007, 3:56am UTC](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897/20 "2007-05-06T03:56:37Z")
[QUOTE=mangeorge] I’ll tell you what I’m going to rmember. I’ll remember that if you break 14 gauge wire, solid or stranded, by twisting on a wore nut, I’ll avoid any contact with you. :eek: And I’ve worked with some pretty rough characters. [/QUOTE] 5’7’’ 130 you got nothing to worry about, but I can tell you I’ve done it a few times. It normally happens when I’m replacing something, so at least one of the wires has already been twisted a few times in the past. Normally though, it doesn’t happen. [Next page](https://boards.straightdope.com/t/replacing-an-outdoor-light-fixture/402897.md?page=2)