Contour V6-153 2.5L DOHC (1996)
3. Allow engine to cool below operating temperature with the ignition switch in the OFF position, remove the Engine Coolant Temperature (ECT)
sensor harness connector and connect the Rotunda Service Coolant Temperature Monitor Harness 007-00064 or equivalent between the
powertrain control module (PCM)(12A650) and the engine coolant temperature sensor (ECT) (12A648). Attach Rotunda Digital Volt-Ohmmeter
014-00407 or equivalent to the monitor harness. Voltage values (0-5 volts) may now be monitored while the engine coolant temperature sensor
retains its connection to the fuel charging wiring (9D930).
NOTE: A ground may be required for some applications.
4. Keep cooling fan motor and fan blade (8600) running during this test (high or low speed may be used). Two methods may be used to turn the
cooling fan motor ON: disconnect the A/C clutch power supply and turn the climate control to A/C ON or disconnect the power supply to the
cooling fan motor and supply 12 volts directly to the cooling fan motor from the battery (10653).
NOTE: Running test with the vehicle in gear or with the A/C clutch engaged (running) will cause improper diagnosis.
5. Place transaxle in PARK or NEUTRAL. Set the parking brake.
6. Start the engine and allow to idle throughout this test. Allow engine to run for two minutes and then record the engine coolant temperature sensor
voltage. Now record engine coolant temperature sensor voltage every 60 seconds. When engine coolant temperature sensor voltage trend changes
direction or only changes slightly (0.03 volt or less) from the previous reading, record this as the water thermostat opening voltage. Compare
measurements to those specified on the following table:
7. If the opening voltage is greater than 0.79 volt (less than 80°C (176°F)), replace water thermostat.
NOTE: When this procedure has been completed, feel the heater inlet and outlet hoses and the underside of the upper radiator hose. The water
thermostat should be removed only if these hoses are cold after 10 minutes of operation.
8. If the water thermostat opening voltage is LESS than 0.79 volt (greater than 80°C (176°F)), water thermostat is good and should not be replaced.
Refer to the Diagnosis By Symptom Chart for further instructions.