Lampost Light Problem
 

My lamppost light stopped working a few weeks ago.

Last week I took the light out and tested it and it was good so I replaced the light sensor and turn the power back on. The light came on for about one minute then went off, I thought I had it fixed but the next night we noted the light did not come on.

Going to take it apart again and see if I can find anything. Is there a way to test the sensor?

Jack

There was a defective batch of sensors (can't recall the brand)...that were being sold by Ace a few years ago.

Maybe there are still some left...from wherever you bought it?

The light turning on for a minute or two after restoring power, is a self-test feature of the sensor. I agree with the other poster, grab a new one and replace the one which isn't working.

Suggestion
 

You do not say if your fixture has only one bulb.

A bulb can stop working with the filament still intact so that is will work sometimes. Try easy first and take a bulb you know is good and install it. If, you have replaced your bulbs with the LEDs they fail weird. It could work sometimes and then not work other times.

Truth, my neighbor with a three bulb fixture replaced the sensor
and then discovered that all three bulbs were blown. As to testing the sensor, you could easily by pass the sensor and see if the lights light.

Got it from Lowes, but that is possible.

update I went out and checked wiring it was correct per what I could find on the internet, Red wire to lamp black wire to post reversed the red to post and black to lamp and seems to working somewhat ok. Light turns on and off when anything hits the post.


I have one blub and it is an outdoor LED that I got from Blubs Plus.


Not sure if I should change the wiring back

Check your ground fault sensor. You might have a short some place in the line and it is turning off the ground fault. Assuming the bulb and the light sensor is good a short in the wiring is most likely the problem. Recheck your connections.

All whites get tied together. The red wire from the photocell gets connected to the black wire from your lamp post FIXTURE. The black wire from the photocell gets connected to your supply/load line, which is the black wire coming from the bottom of your post. When you say it turns on and off when anything hits it, do you mean it literally turns on the light when you hit the post? Also, after restoring power to the post, the light will come on, and eventually go off. If its turning on and off in the daylight, you have a short somewhere, and need it addressed.

Here is a direct answer
 

Don't R&R it, check it. Using your multimeter check the resistance of the photo cell. It is low under light and high with darkness

Pinhead, there should have been a set of wiring instructions with the new sensor, from your description I think your initial wiring was wrong, and the sensor is now toast. The sensor cannot easily be tested without having power on it, I would not bother and just get another sensor and carefully install.
Once installed, take BLACK tape (opaque) and place over the sensor, turn on the power, after a short delay (~60 seconds) the light should come on, take off the tape, it should go out.
If nothing happens, check the GFI in the garage, on of them is probably tripped, reset, and test sensor with tape again.
If the GFI trips again, then I would suspect a short in the wiring. My neighbor actually found wiring with JUST wire-nuts and NO waterproofing on his lamp post. If the problem occurred after a heavy rain I would really look at the wiring in the ground. If the GFI trips due to movement of the lamp post, then you probably have a short to the post and the wiring where the wiring comes into the post below grade.
VERY IMPORTANT: If the above information makes you uncomfortable or you have concerns about doing any of this work, call an electrician.

So, where's the best place to buy the "identical" light sensor. BTW, my lamp post is on the 15 amp general lighting/garage door opener circuit.

Lowe’s, Home Depot, Ace, Amazon.

After spending a lot of time figuring out that it had to be the sensor, I took it back to ACE and they gave me a different brand that worked fine.

As mentioned above, just take the old one to Lowe’s, Home Depot, Ace, Etc....and ask them for one that is compatible (I think most of them are compatible).

I had to buy three lamp post light sensors from Ace(South Trace Plaza) on 466, before the third one worked...Wired them just the same, as I (de)wired.. This, about eight months ago....

I had a problem every time it rained the post light would go out and the GFI would trip. As I finally found, it was water getting into the outside electrical outlet (which is on the same circuit GFI). Replaced the receptical and sealed the outlet. Problem solved.