Article 1297 - Correction to Shop Manual - Speed Control Wiring Diagrams and Set-Speed Switch Diagnosis

TSB #86 - February 23, 1968
(1968 Ford and Mustang)


The wiring diagrams for the 1968 Ford and Mustang speed control systems appearing in the 1968 Shop Manuals and the 1968 Wiring and Vacuum Diagrams book (pages 2-E17 and 4-E25) are incorrect. This article contains the correct wiring diagram to be used when diagnosing problems with the Ford and Mustang speed control system.

Also, the diagnosis procedure for the set-speed switch as listed in part 16-3 of the Shop Manuals is incorrect. The correct procedure is as follows:

    1. Disconnect the set-speed switch connector (green three wire plastic connector at the base of the steering column).
    2. Connect a self-powered test light to the center male terminal and the white wire terminal of the connector.
      • Button in normal position (out) — light should come on.
      • Button in first detent position — light should come on.
      • Button fully depressed - light should go out.
    3. Disconnect the test light lead from the white wire terminal and connect it to the violet wire terminal.
      • Button in normal position (out) — light should not come on.
      • Button in first detent position — light should come on.
      • Button fully depressed - light should go out.

Image
Click to enlarge

cron