How do I troubleshoot a 60" light bar that only works with the key on but not when the truck is running?Updated an hour ago

If your 60" light bar powers on with the key in the “on” position but shuts off once the truck is running, it usually points to a wiring or power source issue. Here are steps to check:

• Confirm that the light bar is wired to a proper 12V power source that remains active while the vehicle is running.

• Inspect the connection point—some ignition or accessory circuits lose voltage once the engine starts. If the light bar is tied into one of these, it will shut off under load.

• Verify the ground connection is secure and making good contact with bare metal. A weak or painted ground can cause intermittent operation.

• Check for cut, pinched, or loose wires that may be interrupting power once vibration from the engine starts.

• Inspect the inline fuse and relay (if used) to make sure they are properly rated and functioning.