The truck runs hot especially when idling. I have changed the thermostat. Should I change the radiator fan relay?

Check and see if the cooling fans are coming on. Check fuses and relays for them.

Run it again. When it gets hot, check to see f the fans are coming on. Check fan fuses and relays. There are other things, but Nissan's are usually good about cooling the engine.

relay that controls the speed of the radiator cooling fans must be checked
Air conditioning works when theAir conditioning works the relay is stuck ON for the fans cool two radiators (ac + main radiator)

Try checking the fan fuses an relays and go ahead and change ur thermostat might be faulty with the extra heat from the motor

Try connecting your fans directly to the battery to know if they are working. If they don't replace your fans. If they are ok, then change the thermostat.
Try this:
When engine cold, remove radiator cap, then fill the radiator with water and start the engine. If water jumps out of the radiator and continues going out as the engine warms up, then you have a bad head gasket and that's why is running hot.

compression test most likely blown head but first why did you change all this stuff if the cause was overheating then am suspecting a blown head gasket

CHECK COOLING FAN FUSE AND RELAY.IF BOTH ARE GOOD.HOT WIRE COOLANT FAN.IF FAN DONT RUN FAN MOTOR NEEDS REPLACING. IF FAN MOTOR RUN WHEN YOU HOT WIRE IT.YOUR FAN MOTOR ELECTRICAL WIRES DAMAGED OR HAS SHORTS OR THE COOLANT TEMPERATURE SENSOR FAULTY.

IF COOLING FAN STAYS ON WHILE CAR IDLING AND DONT TURN OFF YOUR ENGINE IS RUNNING A LITTLE HOT.YOU COULD PARTIALLY CLOGGED RADIATOR OR ENGINE BLOCK PARTIALLY STOPPED UP ALSO THE THERMOSTAT NOT OPEN ALL THE WAY.HAVE VECHICLE SCANNED TO SEE WHAT COOLANT TEMPERATURE IS IF HOT.HAVE RADIATOR SHOP PRESSURE TEST COOLANT SYSTEM AND FLUSH OUT RADIATOR AND ENGINE BLOCK CHANGE THERMOSTAT.

Check your radiator for external and internal obstructions (leaves, bugs etc on the a/c condenser or leaves between the condenser and radiator, rust or calcium deposits inside the radiator core all cause loss of heat transfer)
Also make sure that the system is full and that the electric fan and the clutch fan are operating properly. (electric fan should come on just above normal operating temp and clutch fan should not be "freewheeling" above temp either)
Note: If you need to have the radiator flushed, do it separately from the engine. especially the inline 6 and 4 engines rust up inside and if the system is flushed with the radiator connected, the debris will pack up inside it and actually can worsen the condition.

Take off your radiator cap (when the car is cold) and then start it. If it looks remotely like a geyser in Yellowstone, you have a blown head gasket.