Dell XPS 8500 (Early 2012) - Manual (Page 95)

Replacing the Chassis Fan
1 Align the screw holes on the chassis fan with the screw holes on the chassis.
2 Replace the screws that secure the chassis fan to the chassis.
3 Connect the chassis fan cable to the system board connector SYS_FAN1.
See "System-Board Components" on page 21.
Postrequisites
1 Replace the computer cover. See "Replacing the Computer Cover" on
page 25.
2 Follow the steps in "After Working Inside Your Computer" on page 15.
Chassis Fan 95