Ninety-Eight FWD V6-260 4.3L DSL (1985)
Cold Advance: Description and Operation
This switch is used on some diesel engines to control fast idle speed.
On some vehicles, the switch contacts are closed below 125° F, which completes the circuit and activates the solenoids. At the calibration point, the
contacts open, creating an open circuit which deactivates the fast idle and Housing Pressure Cold Advance solenoids.