1. Open the hood of your Kia Bongo 3.
2. Locate the fuse box. In most Kia vehicles, the fuse box is located in the engine compartment, near the battery. It is usually covered with a plastic cover.
3. Remove the cover of the fuse box.
4. Inside the fuse box, look for the main relay. It is usually a rectangular-shaped device with multiple terminals. The main relay may be labeled "MAIN RELAY" or "MAIN RLY".
5. If you cannot identify the main relay, refer to the owner's manual for your specific Kia Bongo 3 model. The owner's manual should contain a diagram that shows the location of the main relay.
Once you have located the main relay, you can check if it is faulty by swapping it with another relay of the same type. If the problem persists with the new relay, the issue may be elsewhere in the electrical system and it is recommended to consult with a qualified mechanic for further diagnosis.