Will this work with my truck's existing wiring?

Yes. This assembly mounts to factory brake light harness points and uses standard OEM connectors. No rewiring needed.

Does the cargo light function independently from the brake light?

The assembly is a dual-function unit—cargo and brake illuminate through the same housing. They're wired to operate on separate circuits, so you can use cargo mode without triggering brake lights.

What's the return window if it doesn't fit?

Contact customer service directly for return eligibility and timelines. Have your VIN and photos of the mounting area ready.