As explained above, the pre-facelift H4 bulbs have one filament or the other illuminated at a time, but not both.
The facelift lamps have 2 x H7 bulbs, which both illuminate together when on 'High Beam'
You don't need a relay, all you need to do is move one terminal in the main lighting switch connector - same as a factory facelift vehicle.
Remove the cowl around the steering column (3 x screws)
Unplug the main lighting connector
C0041 (there's just enough slack on the loom) -
Use a safety pin (or similar) at the front of the connector, to lift the terminal locking tab above the terminal in cavity 2, while gently pulling on the Blue/Red wire.
This is
C0041 with the terminal locking tab (in cavity 4) being pointed to -
When the terminal is released, re-insert it into cavity 1
Plug the
C0041 back into the main lighting switch, re-fit the steering column cowl - job done
.