Temperature Gauge Sending Unit
The sending unit is located in the front section of the intake manifold in the vicinity of the thermostat.
To check it you will need a Multimeter
OHM meter
How can I check the ENGINE COOLANT TEMPERATURE (ECT) sensor on my 1991 HONDA PRELUDE SI 2.1L
To check if a temperature sensor is working, first, ensure it is properly connected to the power supply and any data acquisition system. Use a calibrated thermometer to compare the temperature reading from the sensor with the thermometer's reading in a controlled environment. You can also perform a continuity test with a multimeter to check for any faults in the sensor's wiring. If the readings are significantly off or if there is no response, the sensor may need to be replaced.
check your fire wall
Check to make sure that the temperature sensor is good. A bad sensor is commonly the cause of the temperature gauge not working.
To check the fan sensor on a 98 escort with the key on disconnect the electrical connector to the temperature sesnor. If the fan come on the sensor is all right.
Code P0113 indicates a intake air temperature sensor circuit high output. Check the connection to the intake air temperature sensor and if that is fine consider replacing the intake air temperature sensor.
Check the temperature sensor. You should be able to find a resistance value in your manual. If it is within specs, check to make sure the wire to the sensor is not grounded. Quick check would be to unplug the wire from the sensor. If the temperature goes down to cold it is probably the sensor. If not, there could be a short in the wire to the sensor. Worst case scenario is that the guage itself is faulty but the sensor or the wire is more likely.
The sensor can be checked for resistance with an ohm meter. The sensor can be checked while cold then hot for resistance change.
Check on the cylinder head. Normally it has two wires.
Check the temperature sensor
To check a coolant temperature sensor, first, ensure the engine is off and cool. Disconnect the sensor's electrical connector, and use a multimeter to measure the resistance across the sensor terminals; compare this reading to the manufacturer's specifications for temperature vs. resistance. Additionally, you can test the sensor at different temperatures by submerging it in water at various temperatures and checking if the resistance changes accordingly. If the readings are out of spec, the sensor may need to be replaced.