Will these work with my truck's existing wiring harness?

These mount at factory fog light locations. You'll need to verify your cab has pre-wired fog light ports — some VN/VNL models shipped without them. If your truck has the mounting points, wiring integration is straightforward with the OEM connector.

Do I need to remove the front bumper to install these?

Access depends on your specific configuration, but these use factory mounting points, so removal is usually minimal. Test-fit before committing — some models allow installation without full bumper drop.

Can I run these as DRL during the day and turn them off at night?

Yes. The halo ring operates independently as a daytime running light, and you can switch the fog function on or off. Wiring configuration determines whether both functions are simultaneous or separate.