Will this work with my truck's factory wiring harness?

Yes. This assembly plugs directly into the OEM connector at the factory brake light location. No splicing or rewiring needed.

Do I need to remove the old light myself, or does it come pre-installed?

You'll remove the old unit and install this one in its place. It's a straightforward swap using basic hand tools—no special equipment required.

What if the light doesn't work after I install it?

Start by checking the factory connector for corrosion or loose pins. If the wiring looks clean and the bulb still won't light, the assembly may have a defect. Contact ModSupply support with photos of your install for next steps.