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Coolant Temperature Lower Than Switch Rating

  1. Disconnect negative battery cable and thermotime switch connector. Connect an ohmmeter between terminal W of thermotime switch and ground.
  2. A very low resistance (continuity) should be measured. Apply 12 volts to terminal G of thermotime switch.
  3. Measure time delay between applying voltage and the ohmmeter reading changing from low to high resistance. Time delay should be as specified. See Thermotime Switch Delay table. Replace switch if it does not meet specifications.
THERMOTIME SWITCH DELAY

Coolant Temp. °F (°C) Switch Rated 59°F (15°C) Switch Rated 95°F (35°C)
14 (-10) 5.7 Secs. 6.5 Secs.
32 (0) 3.5 Secs. 5 Secs.
50 (10) 1.2 Secs 3.5 Secs.
68 (20) n/a 2.0 Secs.
86 (30) n/a 0.5 Secs.
95 (35) n/a 0 Secs.