I have a 2004 s60 volvo and the driverside low beam is very dim and when i turn the high beam on both driverside lights go out . Any ideas

 

start by replacing the bulbs (cheap way of ruling them out) then check the resistance to ground at the bulb sockets and then voltage at the at the socket. I'd look around for any signs of corrosion or bubbling/swelling in the wiring (a sign the copper is corroded) and then check voltage at the relays and to/from the CEM (the central electronics modules on this generation of Volvo have internal relays for the headlights (why they did that I have no idea... but its a common failure point which requires the CEM be rebuilt or replaced).

 

[ (the central electronics modules on this generation of Volvo have internal relays for the headlights (why they did that I have no idea... but its a common failure point which requires the CEM be rebuilt or replaced).[/QUOTE]

Typical manufacturer's ploy - turn a routine $7.50 10 minute repair into a $500+ part that takes an hour or more to replace.