I have a cigarette lighter socket which has stopped working after refitting
a replacement plug from Maplin onto one gadget.

Fuse is OK, cigarette lighter works (gets hot) and I have power at the
bottom contact according to DVM. Also checked that the centre and
associated contacts can supply a handsome current.

But when I fit in an appliance with a cigarette plug, I don't get any power
to the appliance. Have tried a few!

Any ideas as I feel a bit stumped?