are fuses always on 12V side of a device?
 

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

are fuses always on 12V side of a device?
 

are fuses always on 12V side of a device?
 

> 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

Yes. If there is a short to earth anywhere along that path, the fuse blows.
If the fuse were on the earth side, that would not be the case.

You will occasionally see fuses on both sides of the line on systems that
may have multiple paths to ground, like two-way radios. The ground fuse
will blow if the two ground points have appreciably different voltages and
substantial current flows between them.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."