wrote:
> I find a lot of vehicles used "switched earth" system, where devices join
> to a 12 V main wire, and are switched on the earth side. But then, would
> the fuse still be on the hot side for extra safety?
>
> So I believe it should look like this:
>
> 12V--fuse--lamp--switch--earth

Never seen a fuse on the ground side in anything I've worked on. You
fuse the hot side to protect the entire circuit. A fuse on the ground
side would do nothing if the problem is prior to the fuse.

12V--load--switch--fuse--earth

Everything from the 12V feed to the fuse is actually unprotected.

--
Steve W.