Ford Mustang (1999-2004) Service Manual: Inspection and Verification

NOTE: If any concerns are noted with the speedometer, stoplamps, or horn, address those concerns by referring to their associated sections before continuing speed control diagnosis.

1. Verify the customer concern by operating the speed control system.

2. Visually inspect for obvious signs of mechanical and electrical damage.

Visual Inspection Chart

Mechanical Electrical
  • Deactivator switch
  • Speed control actuator cable not attached to throttle
  • Speed control actuator cable not fully seated to the engine bracket
  • Central junction box (CJB) Fuse:
  • 15 (15A)
  • 33 (15A)
  • 35 (15A)
  •  Battery junction box (BJB) fuse:
  • HORN (20A)
  • Wiring harness
  • Loose or corroded connections
  • Speed control actuator switches

3. If the fault is not visually evident, verify the symptom and GO to the Symptom chart.

    Principles of Operation
    The speed control system is designed to maintain vehicle speed above 48 km/h (30 mph). After the ON switch is depressed, depressing the SET/ACCEL switch will activate the speed control servo. To inc ...

    Symptom Chart
    NOTE: New speed control diagnostic software is available in Version 12 or higher for the diagnostic tool. When using this software, it is necessary to use Next Generation Speed Control Adapter 007- ...

    Other materials:

    Connecting Rod - Bearing Journal Clearance
    Special Tool(s) Plastigage 303-D031 (D81L-6002-B) or equivalent NOTE: The crankshaft connecting rod journals must be within specifications to check the connecting rod bearing journal clearance. 1. Remove the connecting rod bearing cap. 2. ...

    Jump-starting the vehicle
    WARNING: The gases around the battery can explode if exposed to flames, sparks, or lit cigarettes. An explosion could result in injury or vehicle damage. WARNING: Batteries contain sulfuric acid which can burn skin, eyes and clothing, if contacted. Do not atte ...

    Charging System (Description and Operation)
    The charging system is a negative ground system consisting of the following: generator internal voltage regulator charging system warning indicator storage battery necessary wiring and cables The generator is belt-driven by the engine ...