If there is a photo sensor between the base of your yard light and your light fixture and the tester does not light up the photo sensor may need to be replaced.
Lamp post light sensor not working.
Warning never connect a light sensor to a live circuit as it is not only dangerous for the individual but it could damage the sensitive circuitry of the sensor.
Turn on the breaker and see if the light comes on.
So if you just bought a new solar light and if it s not working you definitely should check this out.
But if a new bulb doesn t fix the problem.
Test if the sensor is working or not.
Whether your post light is 120 volt or low voltage most lights have a dusk to dawn sensor in the post a small round eye.
The lamp has 3 lights.
I have dusk to dawn sensors in the lamps outside of my garage.
Each light has a dusk to dawn sensor screwed into the socket but only one light will burn at a time.
When darkness falls and a dusk to dawn lamp post fails to light the first thing you should do is check the bulb.
Your outdoor sensor lights are not working or they seem less sensitive than usual.
Most solar lights have a little sensor to check darkness.
When one burns out it has to be replaced before the light will work.
If it does adjust the sensor range and sensitivity as needed.
If the tester does not light there is an issue with the wiring between the base and the top of the yard lamp and the wiring could need to be replaced.
Solar lights don t work during day time in order to check them during day time you need to simulate darkness.
Turn off the circuit breaker that controls the light circuit and leave it off for 30 minutes.
If the light won t come on after adjusting and cleaning the sensor try a simple trick.
How to replace a lamp post photo cell.
Many times this can go bad causing the light to stay on or off.
If your outside lamp post was previously controlled by a wall switch leave the switch on all the time after installing a fixture with a built in light sensor.