A Volvo S40 has headlight assemblies that hold the headlights as well as parking lights, turn signal lights and side markers. Making sure these lights are operational is important to ensuring your safety. Check all of your S40's lights every few months to ensure they are functioning properly. If one of your S40's headlight is not functioning, replacing it is a simple task that should take less than 20 minutes. The S40's low-beam bulb is different from its high-beam bulb; Ensure exactly which bulb is out before you begin.
Open the S40's bonnet and locate the pin that is behind the headlight assembly of the bulb that needs replacement. The pin has a handle on the top. Pull the pin straight out of the headlight assembly.
Push on the back of the headlight assembly until it comes out the front of the S40. There is an electrical connection on the back of the assembly; unplug the connection.
Press on both clamp on the assembly. The clamps are on either side. Push them in together so that the cover releases.
Uncover the bulb by pulling on the small plastic cover that covers each bulb. Push the visible wire aside. Pull the bulb straight out.
Push a new bulb in and push the metal wire back over it to secure the bulb in the assembly. Push the covers back on.
Reconnect the electrical harness to the assembly and push the assembly back into place. Push the retaining pin all the way back down into place.