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?

[Zoobeef]

Its a fuse for a sound system.

Someone had an amp fitted at some pont.

[Tom _M]

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

[Getragdogleg]

You put the fuse as close as possible to the battery. Amp goes in the car somewhere dry.

[ZX10R NIN]

That lead runs to the back of the car where the amp was mounted on the backseat/in the boot.

[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...

[ZX10R NIN]

Wanting good quality sound is irrelevant to what your driving.

[Miserablegit]

Don't touch it.

It's a flux capacitor and if not installed correctly it will take you back to 1985 when the vehicle hits 55mph rather than 88mph.

As others have said it's a fuse for a 12v feed to an amp that the PO must have taken out.

[Spare tyre]

Shame the other end has been removed, could be handy for running something in the boot