Halogen motion sensor light stopped working, Incandescent still works

keyser soze · 05-28-2007, 04:51 PM

Hello all, new to the forum here. This is where I should have been forum'ing the whole time. I've been a member on many other types of forums and never thought about a Home Improvement forum.... until today that is. Now you'll never get rid of me!

A little background is in order before the question,
1912 farmhouse, knob and tube wiring (lights only, I rewired the outlets with romex). They ran all of the wire in the ceiling (T-tapped) and dropped switches from there. Only 2 conductors in each switch box, hot and switched hot. My buddy that happens to be a licensed electrician said they called it "Down on white, back on black" if that means anything to you. All I know is that is a PITA to troubleshoot. Most of the lights have two hot wires when switched off and then one "turns into a neutral" when the switch is on. Odd, yes. Basically switching the neutral downstream from the light. Not so bad once I wrapped my head around it.

I have a light (was a keyless fixture when we moved in, I replaced it with a Halogen motion sensor light that worked fine for several months) in the carport. One day it did not work anymore. There is old wire to the exterior where it goes into a junction box and romex (14-2 WG) to the light.

Here's the freaky part. I do not remember hooking the light up in a unusual manner initially. When it stopped working (both bulbs at the same time) I thought I'd pull it down and check the wires to make sure before I tried new bulbs. Black = cold all of the time - White and ground = hot when switched on... Yeah.

I looked in the J-box and it was the same there except the ground was cut off and not hooked up to anything. If it wasn't for the mysterious ground I would not be worried. The romex is visible and unharmed. I did nothing in that area around the time it went crazy.

I hooked up a incandescent bulb today (random indoor fixture was the first thing I saw) in reverse (white to black and vice versa) and it worked fine. I tried the halogen with new bulbs in reverse (like I did the incandescent)... nothing. What gives?

BTW, I checked the voltage and it's fine (120) but the white is hot and the black is neutral. That's not the craziest thing I've seen here so that doesn't bother me at all. I could care less what color the jacket is as long as the freaking ground isn't hot.

Sorry about the mammoth maiden post but I didn't want to be the newb that asks a question and gives exactly 5% of the info needed to make a suggestion.

Now I go to try a new peice of romex from the J-Box just to see what happens. Thanks in advance for all of the help. I just might have a new place to spend all of my (what shouldn't be) free time.

keyser soze · 05-28-2007, 10:07 PM

I tried hooking up a new piece of romex at the junction box to eliminate the possibility of some unknown problem with the existing romex.

I just had the halogen light over near the J-box and made a little "jumper" just to see if it would work. It did not. I guess the halogen fixture is dead? I know that incndescent fixtures are extremely simple and I wouldn't be surprised if they worked even when hooked up "backwards". This is not the issue here even though the jacket colors were wrong, I had the halogen hooked up correctly both times I tried it today.

Any ideas? I know this is a crazy issue

I think I'm going to get a new motion sensor fixture tomorrow and see if that works. I have a couple of very competent friends that I might be able to con into coming out and taking a look at this too. Especially noe that I've done a little more troubleshooting. The first time I told each of them what I found they shrugged and walked away. I'll be more persistant this time but I would love to figure this one out on my own (well sort of on my own, with your help

)

JohnJ0906 · 05-28-2007, 10:18 PM

Try bypassing the motion sensor. It might have gone bad. (Just a thought)

keyser soze · 05-29-2007, 07:11 AM

good idea, worth a shot for sure.

keyser soze · 05-29-2007, 08:35 PM

Now I have light in the carport! I just went and got another motion light to get it working now and I'll fidget with the other one later just to learn. I'd like to be able to incorporate those types of sensors into my redneck automation system I'll be installing in my next home. I have to keep this one "period correct" but I hope to be out of here this year.

Makes me mad that I spent months in the dark over a $40 light. Oh well. I lived and I learned. That'll teach me to always assume there's a problem with the house not the cheapo light from Home Depot.

Thanks!

JohnJ0906 · 05-29-2007, 08:58 PM

I'll bet I've done literally 100s of service calls, "my light stopped working"
John - "Did you try changing the light bulb?"
Customer - "Uhhh, no"

Often, Its the simple solution!

keyser soze · 05-29-2007, 09:53 PM

yep, the first rule I learned in audio engineering class was...
If it doesn't work, make sure it's plugged in. (not joking, really was the first rule)

Since then (after a 3 hour service call) I added "If it still does not work, make sure the plug has voltage going to it." I learned that one when 1 outlet on a 8 outlet Panamax surge protector was dead. I never would have thought that one would die by itself but it did.