Do I need to wire this myself, or does it plug into the factory harness?

Wiring method and connector type are not specified in product data. Test-fit the assembly before committing to wiring — you may need an adapter or professional installation depending on your truck's harness setup.

Will this work with my truck's factory brake light circuit?

The unit is designed as a direct replacement for factory third brake lights on these model years. Factory wiring should support it, but confirm your truck's electrical system hasn't been modified before installation.

Does the black housing need paint, or is it ready to install?

It ships ready to install in black. No prep or painting needed — mount and wire it as-is.