Sending Unit Test

'98-99 models: 

1. Disconnect the YEL/GRN wire (A) from the coolant temperature gauge sending unit (B).
   Fig 1: Disconnecting YEL/GRN Wire From Coolant Temperature Gauge Sending Unit

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
2. Using an ohmmeter, measure the change in resistance between the positive terminal (C) and the engine (ground) with the engine cold and with the engine at operating temperature.
   Sending Unit Test Table
   
   

   Temperature	133°F (56°C)	185°F (85°C)-212°F (100°C)
   Resistance (Ω)	137	46-30

3. If the obtained readings are substantially different from the specifications above, replace the sending unit.