You did not say what year. On the 1989 Volvo 240 GL, the headlight relay is mounted on the drivers side front fender just back from the battery box. The relay has two plugs going into the bottom and I would say about 1 inch wide, 2 inches long and about 1.5 inches deep.
The relay that you're referring to is the high beam relay. The headlight relay switch is located in the cab of the car behind the brake and gas pedals. You pull back the carpeting and it is mounted to the firewall.
Haynes has a good one
in the center console, under the Radio
it's located beside the passenger side.
My friend has a 1982 Volvo Station Wagon 240 GL that needs headlights replaced, what is the best way to go about this and about how much will it cost?
Behind the center console to the left of blower.
under the dash, driver side
The 1991 Volvo brake light relay switch is located beneath the drivers side dashboard. The brake light relay switch will be above the brake pedal.
It is in the center dash, behind the panel in the left side footwell.
its soldered into the central electronics module (A grey box) which is located behind the dashboard just underneath the main headlight switch.
silver rectangle box located on the inside drivers side fender wall
behind the brake and gas peddle under the carper on the fire wall
Remove the fuse from the fuse box. Or remove the relay.