Greetings Santiagorc. 1.-It would be necessary to check if the fuse was damaged. 2.-It would be necessary to see if the contacts at ground level for the changes are dirty and do not let the current signal pass to both high and both low lights. 3.-Each light has its own relay and for the 4 to be damaged I see it impossible. 4.-Maybe from the terminals of the automatic and where the earth signal comes out, its terminal is isolated and that means that no signal arrives at any of the 4 relays so that they can function accordingly. 5.-It is possible that at the level of the light switch of the aforementioned headlights there is damage by some false contact . It would imply checking to see if one of its cables was detached or there is no longer good contact. Thanks and regards. .