Section 10-03: Speed Control System
1993 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Control Switches Test

 

Tools Required:

Check main feed fuse and stoplamp fuse first. If these fuses are OK proceed with test. Disconnect the 6-pin connector at the amplifier assembly. Refer to the wiring diagram before performing the following checks.

  1. Connect a voltmeter such as Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent across Circuit 151 (LB/BK) and ground. With ignition switch in the RUN position, depress the ON button and check for battery voltage.

    NOTE: Return ignition switch to OFF position after this step.

  1. Connect an ohmmeter such as Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent between Circuit 151 (LB/BK) and ground.
  1. Rotate the steering wheel throughout its full range of motion while making the following checks.
    1. Depress the OFF button and check for a reading between 0 and 1 ohm.
    1. Depress the SET ACCEL button and check for a reading between 714 and 646 ohms.
    1. Depress the COAST button and check for a reading between 126 and 114 ohms.
    1. Depress the RESUME button and check for a reading between 2310 and 2090 ohms.

      If resistance values are above the allowable limits, check the switch assemblies, clockspring circuits and ground circuit.

      Reconnect the 6-pin connector at the amplifier.



Speed Control














CIRCUIT NUMBER CIRCUIT DESCRIPTION GAUGE COLOR CIRCUIT NUMBER CIRCUIT DESCRIPTION GAUGE COLOR
296 IGNITION SWITCH (ACCESSORY) TO AMPLIFIER FEED 20 W/P 6 HORN SWITCH FEED   Y/LG
149 SERVO FEEDBACK POTENTIOMETER + (TO AMPLIFIER) 20 BR/LG 511 BRAKE SWITCH (LOAD SIDE) TO AMPLIFIER DISABLE 18 LG
148 SERVO FEEDBACK POSITION (TO AMPLIFIER) 20 Y/R 676 SENSOR GROUND 18 PK/O
147 SERVO FEEDBACK POTENTIOMETER - (TO AMPLIFIER) 18 P/LB 679 SENSOR SIGNAL TO AMPLIFIER 20 GY/BK
146 SERVO VENT SOLENOID CONTROL 20 W/P 57 AMPLIFIER GROUND 18 BK
145 SERVO VACUUM SOLENOID CONTROL 20 GY/BK 151 AMPLIFIER CONTROL LINE 18 LB/BK
144 SERVO SOLENOID FEED 20 O/Y