What is the reason for one side of the LED daytime running light suddenly not working?
2 Answers
When one daytime running light is on and the other is not, the reasons may include abnormal voltage at the wiring connector, a short circuit in the daytime running light circuit, a malfunction, or a burnt-out bulb. Below are the relevant details: 1. Inspection: Check whether the voltage at the wiring connector is normal. Generally, passenger cars have a voltage of around 12V, while buses and trucks have around 24V. If the voltage is normal, inspect the daytime running light circuit for loose connections, short circuits, or blown fuses. Repair or replace as needed. If none of these issues are found, the daytime running light bulb is likely burnt out and needs replacement. 2. Repair method: If the daytime running light is not working, it is advisable to have it inspected at a 4S shop, as issues involving the lighting system and wiring can be complex. If you are not familiar with the wiring, you may easily damage the original vehicle wiring. Generally, it is difficult to repair such issues on your own.
My old car had this issue before, where one side of the LED daytime running lights inexplicably dimmed. First, consider the common causes: it could be that the LED module burned out—LEDs are durable but can develop problems over time due to thermal expansion and contraction. Or, the fuse might have blown, which isn’t hard to check—just locate the corresponding fuse in the fuse box and replace it. Another possibility is a short circuit or loose contact points, especially after driving through water, as rust can cause disconnections. Additionally, a controller malfunction might only affect one side, but dealing with complex electrical systems requires caution. I recommend checking the fuse yourself first; if that doesn’t fix it, use a multimeter to test voltage and current flow. For prevention, avoid bumping the front of the car and keep the light assemblies clean. Fixing it promptly is crucial for driving safety, as daytime running lights affect visibility. Don’t delay repairs to avoid further complications.
