Could be just the switch (the button you push). To check, pop the center portion of the coin holder between the driver and passenger side seat heater switches. On both opposing short sides of the switch there is a clip that need to be pried open to allow the switch off of the harness.
Just swap the good switch over and if it works, order a new switch.
What heat r u referring to, is it the seat heater. If it is, turn off the seat heater
Yes
Under the hood on the top driver side.
To the left of the driver seat on the floor.
Under the driver seat it is also linked to the reversing sensors
Remove the nuts! They are on the lower metal frame the seat
Sure.Just reinstall the seat belt on back.
under the driver seat, in the undercarriage, And one on the Sump in the tank.
I believe it is under the driver seat. Do you have an LSE?
All Volvo cars have seat belt. Volvo invented the three point seat belt and has used it ever since.
theirs a handle under the front seat push it to the left and the seat will turn to the left at the same time
2, one in the tank, one under the driver seat