What's this wire

[Milky400]

As title says, was lurking under rad.. Assume it's earthing but not connect to anything

[Milky400]

[Milky400]

Thanks, I'll have a look. The radio reception is rubbish and often doesn't pick up a thing, so guess it makes sense. Where would be the best place to ground down there? Was between the engine and air con rads....

Thanks again