Remove the temperature switch.
Caution: The switches are not interchangeable. White smoke will be present if the wrong temperature switch is used.
Notes:
1) The wax motor KSB (used on pre-91 engines) uses a 160°F [71 °C] normally open coolant temperature
switch, Part No. 3915945.
2) The electrical solenoid style KSB (used on 91 models and newer) uses a 9 0 ° F [32°C] normally closed intake
manifold temperature switch, Part No. 3921642.
The operation of the temperature switch for the wax motor style KSB can be checked by connecting a volt ohmmeter
to the switch, placing the switch in water, and then heating the water to 160°F [71 °C].
Connect the VOM to the two pins on the left when viewed with the plastic tang on top.
Check the water temperature with a thermometer.
The VOM should indicate an open circuit below 160°F [71 °C], and a closed circuit above 160°F [71 °C].
Replace the switch if necessary.
