System Diagnosis

Fig. 26 Main Switch Test:

Fig. 30 Cruise Control Unit Voltage Test.:

1. Turn ignition switch then the cruise main switch to the On position.
2. Ensure main switch indicator lamp illuminates. If lamp does not illuminate, proceed to step 3. If lamp illuminates proceed to step 4.
3. Check continuity between terminals of cruise control main switch, Fig. 26.. If switch operates correctly, repair wire harness.
4. Measure voltage at following terminals of the control unit, Fig. 30. If terminal voltage are correct, replace cruise control unit.
5. Disconnect cruise stop lamp and clutch switches and ensure continuity exists between terminals only with pedal depressed.
6. If switches operate correctly, repair wiring to switches.

Fig. 33 Cruise Control Switch Test.:

Fig. 36 Actuator Continuity Test. MX-6 & 626 Less Turbo, Miata & MPV:

Fig. 37 Actuator Continuity Test. MX-6 & 626 W/turbo:

7. Check for continuity between terminals of cruise control switch, Fig. 33. If switch operates correctly, repair wire harness.
8. Disconnect stop lamp switch and ensure continuity exists between terminals only with pedal released.
9. Measure actuator solenoid resistance using an ohmmeter, Figs. 36 and 37. If continuity is not as specified, replace actuator.
10. If continuity is as specified, disconnect actuator cable, start engine and run at a idle.

Fig. 38 Actuator Operational Test. MX-6 & 626 Less Turbo, B2200, B2600, Miata & MPV:

Fig. 39 Actuator Operational Test. MX-6 & 626 W/Turbo:

11. Apply battery voltage to terminals shown in Figs. 38 and 39, and check actuator operation. If not as specified, replace actuator.
12. Remove instrument cluster.
13. Connect an ohmmeter between terminals 1U and 1N on the 12-pin connector.
14. Ensure intermittent continuity between terminals while rotating speedometer cable shaft. If four times per rotation, replace speedometer.