Assuming this is a 4.3 L engine, and assuming you are looking for the coolant temperature sending unit, it is located between #3 and #5 spark plugs on the drivers side cylinder head. It has one wire attached to it.
In the fuel tank. The fuel tank needs to be removed to gain access to the sending unit.
Next to the thermostat housing.
Probably the sending unit inside the fuel tank is bad.
how do you replace the fuel sending unit
There are actually two water temperature sending unit on a 1994 S10 Chevy. Please locate the unit close to the thermostat housing, and not the one between spark plugs. The single wire water temperature sending unit should then be attached to the temperature gauge. The two wire unit, the one between spark plugs, would be connected to the engine control module.
The fuel gauge sending unit in the fuel tank is probably the problem.
The fuel tank has to be removed to gain access to the fuel sending unit. The fuel sending unit and the fuel pump is replaced as a unit.
needs a fuel level sending unit 100 percent sure
In the fuel tank. Fuel tank must be removed to gain access to the sending unit.
Assuming you mean the engine coolant temperature sending unit, we need to know what engine it has, it makes a difference.
With a 4.3L engine, the oil pressure sending unit is in the back of the engine just to the drivers side of the distributor.
If you suspect the sending unit may be faulty just replace it with a new one, they are not expensive but a little difficult to remove and replace.