Upgrading electrical when re-doing siding & code question
You can't run it directly under the siding.

However, depending on how much siding you will remove during the process, it could be easier/cleaner to cut through the exterior sheathing to run new wiring. The cuts you make in the sheathing only have to be sealed against airflow and ambient moisture, unlike drywall which has to look good, too. There is much less work needed to repair exterior sheathing.