Sending Unit Check

Warm sending unit in water and measure resistance. Refer to Fig 1 . Resistance should decrease as water temperature increases.

Fig 1: Testing Metro & Tracker Coolant Temperature Sending Unit

Courtesy of GENERAL MOTORS CORP.

Warm sending unit in water to 122°F (50°C). Using an ohmmeter, sending unit resistance should be about 226 ohms. Heat sending unit to 239°F (115°C). Resistance should be 26.4 ohms.