To diagnose any malfunction with the cruise control system, first perform a thorough visual inspection. Begin by checking all items for abnormal conditions such as bare, broken or disconnected wires, and check for damaged or disconnected vacuum hoses as well. All vacuum hoses should be securely attached and routed with no kinks in them. The cruise control servo (throttle actuator) should operate freely and smoothly, and its cable should be adjusted as tightly as possible without opening the throttle plate or causing an increase in idle speed. Refer to the appropriate portions of this section for information pertaining to servo operation and cable adjustment. Check for a sticking brake and clutch switch (if equipped) as this could keep the system from engaging.
Once it has been determined the system is not operating properly, and all obvious trouble sources have been ruled out, refer troubleshooting to a reputable repair facility.
See Figure 1