Do these mount at the factory fog light openings?

Yes. These use your Ram's factory mounting points — no drilling or cutting into the bumper required. Bolt straight in using existing holes.

Does the wiring harness connect to the factory electrical?

The harness and switch are included. How you tie into your truck's electrical system depends on your truck's current setup — some Rams have pre-wired fog light circuits, others don't. Confirm your truck's wiring before installation to avoid splicing guesswork.

Will these fit if I've already modified my bumper?

These are designed for stock bumpers. If you're running an aftermarket bumper or have cut/reshaped the fog light opening, test-fit the bezel and housing before committing to installation.