What Does This Error Mean?

E-bike lights not turning on are usually caused by lights being toggled off in the display menu, or a loose wiring connector at the light housing. Check the light toggle button on the display and inspect the connector at the base of each light.

Affected Models

Rad Power Bikes
Lectric XP
Aventon
Trek e-bikes
Most hub-motor e-bikes with integrated lighting

Common Causes

Lights toggled off via the display or handlebar button
Loose or disconnected waterproof wiring connector at the light housing
Blown inline fuse in the lighting circuit
Water ingress into the light housing shorting the LED module
Battery critically low — some bikes disable lights below 10% to preserve motor power

How to Fix It

Toggle the lights on using the display button.

On most e-bikes, lights are controlled by a dedicated button on the handlebar display — often a sun icon or light bulb symbol. Press it once to turn lights on; some bikes require a press-and-hold. Check the display settings menu if no dedicated lighting button is visible on the controls.
Inspect the wiring connector at the light.

Follow the light cable from the housing to where it plugs into the main wiring harness. Disconnect and firmly reconnect the waterproof connector. A loose connector is one of the most common causes of e-bike lights failing after riding on rough terrain.
Check the inline fuse.

Some e-bike models include an inline fuse in the lighting circuit, usually located near the controller box or battery tray. Consult your bike's service manual for the fuse location. Replace a blown fuse with one of the same amperage rating.
Check the battery level.

A critically low battery (under 10%) causes some e-bikes to automatically disable the lights to preserve motor power for riding. Charge the battery to at least 50% and check if the lights return.
Inspect the light housing for water damage.

If the light lens is cracked or the seal around it has failed, water ingress can short the LED module. Look for fogging or condensation inside the lens — this means the seal has failed. A sealed light with visible moisture inside will likely need replacement.

When to Call a Professional

If the connector is secure and the fuse is good but the light still does not work, the LED module inside the housing may have failed. Most e-bike shops can replace integrated light modules at low cost.