How do I fix truck bed lights that won’t turn on?

Locate and toggle the truck bed light switch to ensure it is turned on. Inspect the fuse box and identify the fuse for the truck bed lights using the owner's manual. Remove the fuse and check if it is blown; replace it with a fuse of the same rating if needed. Use a multimeter to test for voltage at the fuse terminal with the switch on. Check the wiring harness leading to the bed lights for visible damage or corrosion. Use a multimeter to test for continuity in the wiring from the switch to the light housing. Inspect the ground wire connection near the truck bed for rust or looseness and clean or tighten it. Remove the light housing and check the LED or bulb for signs of damage or burnout. Replace the bulb or LED module if it appears damaged or does not light up when tested. Use dielectric grease on connectors to prevent corrosion before reconnecting them. Secure all wiring using electrical tape or wire connectors as needed. Reinstall the light housing and ensure it is properly sealed against moisture. Turn the truck ignition to accessory mode and test the bed lights again. If lights still fail, test the switch itself for continuity and replace if faulty. Verify that all connections are tight and free of corrosion or debris. Check for any aftermarket modifications that may interfere with the lighting circuit. Ensure the truck's battery is charged and supplying proper voltage. Test the lights in both daylight and low light to confirm proper operation. Document any replaced parts for future reference or warranty claims. Dispose of old fuses or bulbs properly according to local regulations.