All sorted. The problem was exactly as suspected - the spotlights had been wired directly in with the main beam and therefor protected only by the 15amp fuse 13. My mistake - I thought it was 10 amp.
The engineer installed a new spotlight feed from the 40amp fuse via a diode relay.
Moral of the story is perhaps not to assume any aftermarket electrical accessories have been correctly installed - even when the car is bought from a main dealer.
A plug for Dave Burton from Stoke-on-Trent on
https://dbautoelectrics.com A thoroughly decent guy who takes time to explain what he is doing and why and does not charge the earth for his services. He had previously fitted fancy LED headlights for a couple of DevaMog members to my knowledge.
Next task is to convince SWMBO the car is now safe to drive in the dark😜
