My 2.0D Saloon SR turns of everything apart from engine when I turn High beam on or Flash the Highbeam while driving

When I turn off car don't have battery backup

When last time I had this problem electrician changed terminal of battery

Car was okay while intercity driving
It happened today again on GT road

When cars starts it take 1 sec of ignition

No second ignition is required
engine in 92k yet
Help required!!