Section 01-20A: Restraints, Active
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

  

PINPOINT TEST A: SAFETY BELT WARNING SYSTEM

 

A1 CHECK SAFETY BELT WARNING CHIME SYSTEM FUSE

Yes
GO to A2.

No
REPLACE fuse.

 

A2 CHECK FOR VOLTAGE AT CIRCUIT 640 (R/Y)

Yes
GO to A3.

No
CHECK Circuit 640 (R/Y) back to ignition switch . SERVICE as required. REPEAT A2.

 

A3 CHECK FOR GROUND AT CIRCUIT 676 (PK/O)

  • Connect a 12-volt test lamp between Circuit 640 (R/Y) and 57 (BK) in safety belt warning chime connector.
  • Turn ignition switch to RUN.
  • Does test lamp light?
Yes
GO to A4.

No
CHECK Circuit 57 (BK) back to body ground. SERVICE as required. REPEAT A3.

 

A4 CHECK CIRCUIT 450 (DG/LG) AND SAFETY BELT WARNING INDICATOR LAMP

  • Connect jumper between Circuit 450 (DG/LG) and Circuit 640 (R/Y) in safety belt warning chime connector.
  • Turn ignition switch to RUN.
  • Does safety belt warning indicator lamp light?
Yes
GO to A5.

No
CHECK Circuit 450 (DG/LG) back to safety belt warning indicator lamp . CHECK safety belt warning indicator lamp . SERVICE as required. REPEAT A4.

 

A5 CHECK FOR GROUND AT CIRCUIT 85 (BR/LB)

  • Unbuckle driver side safety belt.
  • Connect a 12-volt test lamp between Circuit 85 (BR/LB) and Circuit 640 (R/Y) in safety belt warning chime connector.
  • Turn ignition switch to RUN.
  • Does test lamp light?
Yes
GO to A6.

No
CHECK Circuit 85 (BR/LB) back to safety belt warning indicator switch . SERVICE as required. REPEAT A5.

 

A6 CHECK FOR GROUND AT CIRCUIT 158 (BK/PK)

  • Connect a 12-volt test lamp between Circuit 158 (BK/PK) and Circuit 640 (R/Y) in safety belt warning chime connector.
  • Turn ignition switch to RUN.
  • Does test lamp light?
Yes
GO to A7.

No
CHECK Circuit 158 (BK/PK) back to ignition key cylinder switch. SERVICE as required. REPEAT A6.

 

A7 CHECK FOR VOLTAGE AT CIRCUIT 159 (R/PK)

  • Connect a 12-volt test lamp between Circuit 159 (R/PK) in safety belt warning chime connector and ground.
  • Open driver door.
  • Does test lamp light?
Yes
GO to A8.

No
CHECK Circuit 159 (R/PK) back to courtesy lamp switch. SERVICE as required. REPEAT A7.

 

A8 CHECK FOR VOLTAGE AT CIRCUIT 14 (BR)

  • Connect a 12-volt test lamp between Circuit 14 (BR) in safety belt warning chime connector and a known good ground.
  • Pull main lamp switch ON.
  • Does test lamp light?
Yes
System operating properly.

No
CHECK Circuit 14 (BR) back to main lamp switch. SERVICE as required. REPEAT A8.