On Fri, 4 Dec 2015 15:42:46 +0000, Tim Lamb wrote:

What you've written does not make sense. If you take the fuse out
of
course one side of the fuse socket will have voltage - from the
battery; ...

When the lights are supposed to be on ...

... and the other side - to the light - will not.

So if the fuse is good it will carry the current from one side of
its
socket to the other. What might be happening is that the fuse is
not
connecting properly in the socket. Or that when mechanically
stressed
by insertion into the socket it actually goes open-circuit. I
suggest
you try a new fuse in its place.

Or swap with the good one?

Which may become a bad fuse if there is an overload in that circuit,
same for a nw fuse of course. Is the OP checking the fuses visually?
It is sometimes not visually obvious that a fuse has blown, it needs
an elctrical test really.

--
Cheers
Dave.