Do these mount at the factory fog light locations?

Yes, these are designed for factory mounting points on your Escalade. No drilling or custom bracket work needed.

Will I need to run new wiring for the switch?

The switch comes integrated with the assembly. Route the harness to your preferred location—most buyers run it under the dash or to an existing switch panel. Exact routing depends on your setup.

Can I replace just the bulb if it burns out later?

Yes, the 899 bulb is standard and widely available. You can swap in a replacement without any tools or disassembly beyond the lens cover.