Do these use factory wiring or do I need new harnesses?

They're designed to plug into your existing corner light connectors. Confirm your current wiring supports LED before install — some factory harnesses need a load resistor to prevent hyperflash.

Will these fit if I'm running an aftermarket front bumper?

Test-fit before final install. Aftermarket bumpers vary in mounting depth and bracket placement. Measure your corner pocket dimensions against the lens diameter to confirm clearance.

What's the return window if they don't work with my setup?

Check the return policy at checkout. Since these are brand new electronics, most retailers require a functional test video — have it running before you seal the return.