A quick update, thanks again to everyone whose responded.
I have checked that the cigarette socket is live when the ignition is off: I can confirm the socket is live, I have a 12 volt light that plugs into cig socket and that worked.
Fuse in the plug is intact, I couldn’t read what it was rated at though but the details on Amazon say it is fitted with a 10amp fuse - so presume that it is.
I think the wiring is the right way round, as the charger shows all being well for a few seconds then the error light comes on. I would think a wiring issue would be binary- it would work or it wouldn’t.
Ivor Mog - you make a very good point, I can’t argue your logic!
So tomorrow CTEK 5.0 will be procured...
Thanks again for all the pointers.
Get it hard wired, not difficult. There have been cases where cars have caught fire using the power socket.
