In the same LED light bar, why some LEDs on while others are not working ?

Some people may get a problem with they mount their light bars on old vehicles. Some LEDs on while others are not. How could this happened ? Check your battery and wire harness. Most of the time is because that the power is not enough for the LEDs. For example, when you put a 240 Watt light bar on a Jeep, you'd better make sure your battery is 12V/16A or 24V/8A. It can be higher, but can't be lower. If you checked this and still the light bars not work perfectly, find your supplier to see how to solve this problem.

Another possibility is that the wiring wastes too much of the power. People would think that the longer the better if they spend the same amount of money on the wiring. But in fact, longer wire will not earn you any penny, but wasting your power / energy. 2.5 meter or 3 meter for a light bar is enough.