How to Fix Flickering Under-Cabinet Lighting

Flickering lights are more than just a nuisance; they are a sign of an electrical inconsistency that can shorten the lifespan of your fixtures. Under-cabinet lighting systems, especially LED strips and pucks, are sensitive to voltage drops and hardware mismatches that standard overhead lights often ignore. Getting this right means systematic elimination of variables. You are going to look at the power supply first, then the connections, and finally the control switch. When done well, your lighting will be steady, silent, and reliable, providing the consistent workspace illumination you need for cooking.

1. Spot the Failing Driver. Check the LED driver or transformer for heat or audible humming. If the driver is overheating or makes a buzzing sound, it is likely failing and needs immediate replacement with a compatible voltage rating.
2. Secure Every Wire. Turn off the main circuit breaker, then open the junction box or terminal block where the lighting connects to house wiring. Inspect for loose wire nuts or oxidized push-in connectors and tighten any slack.
3. Test the Dimmer Switch. If you use a dimmer switch, verify it is rated for 'LED load' or 'Magnetic Low Voltage' depending on your fixture type. Standard incandescent dimmers often cause rapid strobing or flickering in LED systems.
4. Clean Connection Points. Under-cabinet systems are often daisy-chained together. Inspect the physical jumper cables between light bars for frayed ends or poor contact points at the snap-in clips.
5. Add Secondary Power Feed. If your light strips are very long, the voltage may drop by the time it reaches the end of the run. Check the voltage at the furthest fixture; if it is low, you need to provide a secondary power feed to that end of the strip.
6. Verify Steady Light. Once connections are tightened and components are verified, turn the power back on and cycle the lights through their full range. Observe for 5-10 minutes to ensure no heat buildup returns.