Fuel/Temp Voltage Regulator
Are you are having problems with either your fuel or temperature gauge? In most cases it will end up being the temperature/fuel gauge voltage regulator. This rectangular box is mounted underneath the dash below the steering column. It provides the proper voltage to both gauges. If your fuel gauge does not work and you know you have gas in the tank it could very well be the voltage regulator. Make sure to check it with igniton switch on. They are relatively cheap and not that hard to replace. There is an inspection door in the trunk. Remove the four bolts securing it and check the connections there to the gas tank sensor. Same goes for the temperature gauge. Double check the wiring going to the sensor on the engine.
Early PN 25020-14600-Late PN 25020-25900
For a 2000, the temp sensor is located behind the thermostat and housing. Just follow the top radiator hose back to the engine. There's a spacer block behind the thermostat housing; it has the temp sensor with an electrical contact sticking out. There should be a a wire connected to it. If you ground that wire at the engine with the ignition on, you should get a reading on the temp sender. If not, then you have a short in the wire or a problem with the temp gauge. If you do get a reading, then your problem is the temp sender at the engine. It's an inexpensive part to replace, but often a pain to remove. On a 1600, the temp sensor is on the drivers side of the engine, just behind the water pump.