Fog light

Very possible. Those can be tricky to find. There are a few tools that can make it easier though. Some parts stores even have them as a loaner tool. The one I have used for a long time is like the picture. The tube with wires is a self resetting circuit breaker. In use the circuit breaker replaces the fuse, as it trips and resets it creates a magnetic field in the wire which makes the needle oscillate. You just follow the wire and when you get to the short the needle stops.

The other type uses a radio signal and a receiver that you use in much the same way.
Both are a big help with shorted wires, the radio version however can be used for finding open circuits as well as shorted.

Looking at the diagram it appears that a short would be in the light green wires. Should not be hard to trace the wire from the light and see if it is pinched, chaffed or damaged.