Electrical Newbie question

[MichaelDo]

I just replaced an old security light for a neighbor. Removed old unit, cleaned out the box, black wire to black, white wire to white, switched on test, and nothing. The sensor clicked and sensor red light flashed, but no lights.

I checked the leads before installing and did have 110v. The neighbor did have problems with this building (garage) previously and I encouraged him to have a licensed electrician fix it. Whoever wired the garage had not split the 220 properly and one light switch worked; it turned on the light, but tripped a breaker in the house.

That electrician fixed the 220v problem between house and garage.

Now I'm wondering if my security light problem is another "first electrician" problem. If that guy used the neutral as a ground from the box to the outlets, would I still test 110v between black and white?

 

[JerryR]

Is the “sensor” a combo motion and daylight sensor? If so you must put it in test mode to get the bulbs to light to test for motion during daylight.

 

[Sponsor]

 

[WorthFlorida]

Open the unit up and be sure the wires to the light fixture did not accidently came loose. Generally, all the Blacks and Whites will have a crimp connection that is pretty bulletproof. In test mode the lights should come on. I don't think you have a neutral problem since you see the LED and hear the relay operate.

Neutral and ground originate from the same location in the circuit panel. The difference it the white neutral carries current, the green is not suppose to carry current but it will still work as a neutral. Either way you will read 110v from the black to the white or green (ground). The green ground serve as a path to ground to trip the breaker should a hot lead touch a metal surface (short).