Stupid Outdoor Light Turns Itself Off And On! (Home Depot, paint, installing)

[KevK]

I have never seen the likes of this. We have had a light outdoors in the back for years. Was here when we got the place. It is a mecury vapor (blue) light and it turns itself on at night and off in the morning. It is mounted on the outside wall of the house over the back deck and under the eve.
Recently we had the gutters replaced with gutters that have the top on them- mainly because I am sick of having to clean the old ones out. After the gutters were replaced, the damn light now turns itself on, stays on for a minute and then turns itself off for a minute and back on for a minute! I finally just climbed up and unscrewed the damn bulb.
I thought maybe the gutter people damaged it but I do not see any visible damage and the gutter is like 2 feet over it. Any ideas or is the thing just shot?

[pinetreecity]

Some thoughts:
Perhaps the gutter work got the light sensor dirty.
If the new gutters are shiny and clean, then perhaps they are reflecting the light back onto the sensor, making it think it is daylight when it comes on.
The light fixture may simply be degrading.

[KevK]

Originally Posted by pinetreecity

Some thoughts:
Perhaps the gutter work got the light sensor dirty.
If the new gutters are shiny and clean, then perhaps they are reflecting the light back onto the sensor, making it think it is daylight when it comes on.
The light fixture may simply be degrading.

You know what?? You might be onto something there.... the old gutters were painted and the new ones are not and they are shiny... tomorrow I am gonna spray some dark paint on the part that is near the light and see if that gets rid of this stupid trouble. I never thought about that causing the trouble but the eye is on top the light and the gutter reflects the porch light too.

[windtimber]

Sounds like a bad photocell. It's usually on the very top of the fixture and has a "twist-lok" sort of configuration. I don't recollect the cost of a replacement, as it's been years since I bought one, but you might check that.

Or you're getting the reflections as noted. But that seems like a long shot...but who knows?

[Coldjensens]

I think that the photocell costs about $15. They can be hard to find. I finally gave up and just paid $40 for a new light fixture and took the photcell out. then it occurred to me that I could proabbly have found one on the internet. - Duh.

[KevK]

Originally Posted by Coldjensens

I think that the photocell costs about $15. They can be hard to find. I finally gave up and just paid $40 for a new light fixture and took the photcell out. then it occurred to me that I could proabbly have found one on the internet. - Duh.

Well I tried to cover the photo switch up with black tape so eliminate the gutter reflecting- same crap- so I just took the fixture down and will grap a new at Home Depot tomorrow.

[GloryB]

Well....I was gonna suggest your place was haunted.....but I suspect the photo switch is the real culprit. Good luck with installing the replacement.

[Thegonagle]

Have you tried just replacing the bulb?

When any type light that produces light with an arc (sodium, metal halide, mercury vapor, etc.) does that, the first thing to do is replace the bulb.

Such bulbs each have two electrodes. An electrical arc jumps between the two electrodes in order to produce light. As the bulb ages, the electrodes slowly burn away, which means the arc has to jump a progressively longer gap. As that gap gets longer, the voltage required to sustain the arc gets higher. Which means the ballast works harder, making it hotter.

Eventually, the ballast would overheat, except for a thermostatic switch inside the ballast, which cuts the power before that happens. After the ballast cools back off, the thermostat turns the power back on, the lamp restarts, and the cycle repeats, usually every 2-5 minutes.

Try changing the bulb before you scrap the entire fixture.

[KevK]

Originally Posted by Thegonagle

Have you tried just replacing the bulb?

When any type light that produces light with an arc (sodium, metal halide, mercury vapor, etc.) does that, the first thing to do is replace the bulb.

Such bulbs each have two electrodes. An electrical arc jumps between the two electrodes in order to produce light. As the bulb ages, the electrodes slowly burn away, which means the arc has to jump a progressively longer gap. As that gap gets longer, the voltage required to sustain the arc gets higher. Which means the ballast works harder, making it hotter.

Eventually, the ballast would overheat, except for a thermostatic switch inside the ballast, which cuts the power before that happens. After the ballast cools back off, the thermostat turns the power back on, the lamp restarts, and the cycle repeats, usually every 2-5 minutes.

Try changing the bulb before you scrap the entire fixture.

Tried that. And the damn bulb cost over $10! So yesterday I just bought a whole new fixture from Home Depot and climbed up and replaced it. I guess I will just keep the extra bulb as a spare. The new one is working fine so far.

[Stone3274]

I've got an outdoor light, commercial, that attaches to the side of buildings. It has worked fine for 15 years, all of the sudden the light is going on and off, changed the light bulb, still does it. Any help with this problem would be appreciated