Any idea what this wire is on my TJ?

Most likely factory wiring for a fog light setup.

Looks like it might’ve been built on a Friday or Monday. Quality control at Chrysler isn’t always the best!

As others mentioned, it’s likely fog lights. There’s also a chance it’s for the side signal on the fender flares. When I replaced my fenders on my JK, I deleted a similar one.

Most likely for fog lights.

Could be extra wiring for a full lighting setup.

That could actually be for an engine block heater. My old Jeep had one—kept it plugged in overnight during winter to keep the engine warm.