Not totally sure on that model. Start up by the fan hub and find the 1/4 in air line going into it. Follow that airline and it will lead you to the solenoid
If your truck is equipped with an ON/OFF air fan clutch the fan solonoid is located just above the LH front wheel (above the black plastic inner fender under the main cab harness) on a braket attached to the fire wall,the original solonoid is steel and most of the time the 1/4 plastic air tubing is green. The replacement solonoid is now full plastic black (if you buy it you will need also a little jumper harness to match the new connection style of the solonoid to the main cab harness.
Ben