It seems that the issue is related to the plate lights/lateral lights (the orange ones).
I checked and the plate lights are ok, but the circuit is shorted between the wires.

But the lateral ones aren't simple to remove, their connector is locked in the bodywork.

Welcome to MVS, ElVentu. Dimmer is the correct term, yes. I'd look for wires chafing/rubbing against other wires, near the headlights. Sounds like a short circuit. Thank you for the reply! But the fuse that popped isn't related to the headlights, and they work fine. It's the internal lights that do...

Hello to everyone, I'm Davide from Italy. I own a 1997 Volvo S40, 1.8 116hp, for 10 years now. What a car, never had major issues. But I have an issue now. :D Just some context. In last days here it was freezing cold. When starting the car on the coldest morning, during cranking the battery had some...