Where is the headlight relay on a 2007 S40 Volvo?

The headlight relay on a 2007 Volvo S40 is typically located in the engine compartment fuse box. To access it, open the hood and find the fuse box on the driver's side near the battery. The relay will be labeled in the fuse box cover; consult the diagram for the exact position. If you're unsure, refer to the owner's manual for more details on the relay's location and function.