What’s this thingy?

[Tom _M]

Have an 07 Focus diesel that have had a few months or so, and eventually got round to giving it a service. Found a strange thing that is wired into the passenger fuse box, but the other end has been removed. Has a hard plastic case and a piece of metal inside, kind-of like a fuse. Any ideas what it was for?

[Tom _M]

Ah okay, guess it makes sense. Would you normally stick an amp in the engine bay though?

[Tom _M]

Ah, thanks. I am now enlightened! Why you’d want a fat sound system and amp in a diesel Focus estate is perhaps another matter though...