Just to the side of the thermostat housing.
low coolant
The coolant temperature sensor is near the thermostat outlet at the front of the engine. You are facing the engine. It should be located to the right of the thermostat outlet. The sending unit on the left of the thermostat outlet, is the temperature gauge sending unit.
its the sending unit
We need to know which sending unit you speak of. There are several on that vehicle such as temperature sending unit, oil pressure sending unit and fuel gauge sending unit.
The sensor is right behind the thermostat housing.
Center of gauge. 180-220 FCenter of gauge. 180-220 F
It is located to the left of the thermostat housing for the temperature gauge, there is another to the right of the thermostat housing for the computer.
The normal problem is with the sending unit in the tank, on the pump module. You will have to remove the tank and pump to replace.
In the fuel tank in the fuel pump assembly. It has a float attached to it, and can usually be replaced separately from the pump assembly.
-faulty oil pres. sending unit -faulty oil pump
It is the center gauge in the instrument cluster.
The normal causes of an inoperative fuel gauge is the sending unit in the tank. Since the truck is 15+years old you might as well replace the fuel pump when you have the fuel tank removed.