Okay, flickering or blinking LED floodlights after replacing them and the photocell is a common issue with a few potential causes. Here's a breakdown of things to check and try, starting with the most likely

1. Photocell Compatibility & Wiring
Voltage Compatibility



This is the most likely cause. Make absolutely sure your photocell is rated for LEDs and is rated for the voltage and wattage of your lights. Older photocells designed for incandescent or halogen lights often don't work well with the low power draw of LEDs, causing the cycling. Some may even be incompatible with LED drivers. Check the photocell packaging or the manufacturer's website for this information. Specifically look for photocells that are stated to be compatible with LEDs. Photocell Wiring

Double-check that you've wired the photocell correctly. Incorrect wiring can cause erratic behavior. The wires are typically labeled or color-coded. Typical set up is:

Black Wire (Line/Hot)

Connects to the black (hot) wire from your power source.

White Wire (Neutral)

Connects to the white (neutral) wire from your power source AND to the white (neutral) wire of your floodlights.

Red Wire (Load/Switched Hot)

Connects to the black (hot) wire of your floodlights.

Photocell Sensitivity Adjustment (if applicable)

Some photocells have an adjustment for sensitivity. If it's set too sensitive, it might be picking up stray light reflections (from your own house, a car, etc.) and cycling on and off. Try adjusting the sensitivity.

Photocell Location

Make sure the photocell is not directly illuminated by your new floodlights or other nearby lights. It needs to be in a location where it can accurately sense ambient light.

2. LED Driver Issues LED Driver Compatibility

The internal LED driver (built into the floodlight) might be incompatible with the photocell's switching behavior. Some drivers are more sensitive to voltage fluctuations or rapid on/off cycles. This is less common with newer LEDs, but still possible.

LED Driver Failure

If the LED drivers are faulty, they can cause blinking. This is more likely if the lights were inexpensive or have been exposed to extreme weather conditions.

3. Wiring Issues Loose Connections

Carefully check all wire connections in the junction box where you wired the photocell and the floodlights. A loose connection can cause intermittent power delivery, leading to blinking. Use wire nuts or other approved connectors, and make sure they are securely tightened.

Shared Neutral

It's critical that the neutral wire is properly connected. Problems with the neutral connection can cause a variety of electrical issues.

Grounding

Ensure that the floodlights are properly grounded. A missing or poor ground can sometimes cause strange behavior.

4. Voltage Drop Long Wire Run

If you have a very long wire run from the breaker panel to the floodlights, you might be experiencing voltage drop. This is more likely with thin gauge wire. Voltage drop can cause the LEDs to flicker, especially when they first turn on.

Overloaded Circuit

Are there many other devices on the same circuit as the floodlights? An overloaded circuit can cause voltage fluctuations. Try turning off other appliances/lights on that circuit and see if the blinking stops.

5. LED Quality Cheap LEDs

Very inexpensive LED floodlights sometimes use lower-quality components, including drivers that are more prone to failure and flickering.

LED Manufacturing Defect

It's possible (though less likely) that one or more of the LED floodlights has a manufacturing defect.

Troubleshooting Steps


Start with the Photocell



Bypass the Photocell (Temporarily)

Disconnect the photocell and directly wire the floodlights to the power source (black to black, white to white).

IMPORTANT: This will mean the lights will be on all the time. Do this only to troubleshoot, and disconnect it when you're done. If the lights stop blinking when wired directly, the problem is almost certainly with the photocell, its wiring, or its compatibility. Replace the Photocell

If bypassing the photocell resolves the issue, and you're sure it's wired correctly and is compatible, try a different photocell, preferably one specifically marketed as compatible with LEDs.2.

Check Wiring



Turn off the breaker before inspecting any wiring. Carefully examine all wire connections for tightness and proper insulation. Make sure the neutral and ground wires are securely connected.3. Isolate the Floodlights

If you have multiple floodlights, try disconnecting them one at a time (again, with the breaker off) to see if one particular light is causing the issue.4.

Consider the LED Lights

If you've tried everything else and the lights are still blinking, it's possible there's an issue with the LED floodlights themselves. If possible, test them in a different location with a known-good power source.

Safety First! Turn off the power at the breaker before doing any electrical work. If you're not comfortable working with electricity, hire a qualified electrician. Always use proper safety equipment, such as insulated gloves and eye protection.Good luck! Let me know what you find out when you've had a chance to check these things. We can refine the troubleshooting from there. Flag for review