Do these fit the stock wiring harness and switch?

These housings are bare — no connectors. You'll either wire them into your factory system or run custom wiring. Check your RAM's original harness before ordering if you plan to reuse it.

Will I need fasteners to install these?

They mount at factory rocker points with existing bolt holes. You'll use your truck's original hardware — no additional fasteners required.

Do these housings need paint or prep before install?

They arrive ready to mount as-is. The clear lens is pre-finished. If you want a different look, prep and paint the housings before installation.