Coolant Temperature Sender

TESTING

1. Detach the single wire harness connector from the temperature sender.
2. Ground the connector to the engine block and verify that the gauge has gone to full HOT reading.
3. If the gauge is working, proceed with the test procedure. If not, inspect the wire harness between the sender and the gauge.
4. Remove the coolant temperature sender from the engine.

   Fig. 1:Submerge the end of the temperature sender in cold or hot water and check resistance

5. Place the sender unit into a container of water.
6. Attach an ohmmeter to the coolant temperature sender connector and the sender body.
7. Heat the water to the temperature specified and read the meter.
   • 1990–92 626 and MX-6 models: 49–58ohms at 176°F (80°C)
   • 1995–98 Protege models: 153ohms at 129°F (54°C)
   • All other models: 190–259ohms at 122°F (50°C)
8. If the meter does not read as specified, replace the sender.