Outdoor solar lights have the advantage of providing free lighting without needing to be hardwired. Despite the simplicity of the design, they do sometimes develop problems. The good news is that most of the problems are easy to troubleshoot and fix.
The very first thing to check on your outdoor solar light is the on/off switch. If it’s switched off, your light isn’t going to work. Simply turn the light switch to the "on" position, and it should work properly.
Strange as it might sound, it's the level of darkness that dictates whether an outdoor solar light works or not. Solar lights rely on a photocell to judge the level of darkness and the level of light. If it’s not dark enough (and the switch is on), the light simply won’t come on. This could be due to the proximity of a street light or lighting from the house. The way to test this is by putting your hand or something opaque over the photocell which is on the top of the light. If the outdoor solar light comes on with no problem, the location is probably the problem and you’ll need to move the light to a place where it’s away from other light sources. This might only need to be a few feet since small distances can make a big difference. The alternative is to have a small circle of black duct tape or electrical tape on the photocell at night.
Another reason why your outdoor solar light won't work could be because the battery isn’t properly seated in the fixture. Given that most outdoor solar lights are made in Asia and then shipped thousands of miles, it’s perfectly possible that the battery would have become dislodged.
This is easy to check. All you need to do is open the fixture and check the battery position. Push the batteries back in place and try the light again.
An outdoor solar light fixture gets its power from the sun. Like all batteries, the one in the fixture has a limited life usually between 2 and 3 years, but eventually, the battery will fail.
Even if only one battery in the light doesn't work, the light itself won’t work. The simple way to check is to test the batteries with a battery tester or an ohmmeter. You can also check by replacing the batteries since they’re usually standard AA batteries which are easily and cheaply available at the store. Many people will already have a few spare batteries sitting around the home. You should also check the terminals and the tips of the batteries for corrosion which could also cause the batteries not to work.