Section 13-09B: Gauges, Warning Devices— Chime/Buzzer System
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

  

PINPOINT TEST A: WARNING CHIME INOPERATIVE

 

A1 CHECK FOR SUPPLY VOLTAGE 

Yes
GO to A2 .

No
GO to A3 .

 

A2 CHECK FOR IGNITION SUPPLY

Yes
GO to A7 .

No
GO to A5 .

 

A3 CHECK SUPPLY CIRCUIT 640 (R/Y)

  • Disconnect warning chime module.
  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 9, Circuit 640 (R/Y).
  • Check resistance.
  • Is resistance 5 ohms or less?
Yes
SERVICE Circuit 640 (R/Y) for short to ground. REPLACE fuse 15 (10A). RESTORE vehicle. RETEST system.

No
GO to A4 .

 

A4 CHECK CIRCUIT 640 (R/Y) FOR OPEN

  • Disconnect ohmmeter lead from ground and connect lead to output side of fuse 15 (10A).
  • Is resistance 5 ohms or less?
Yes
REPLACE fuse 15 (10A). RESTORE system. RETEST vehicle.

No
SERVICE Circuit 640 (R/Y) for open circuit. RESTORE vehicle. RETEST system.

 

A5 CHECK SUPPLY CIRCUIT 296 (W/P)

  • Disconnect warning chime module.
  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 8, Circuit 296 (W/P).
  • Check resistance.
  • Is resistance 5 ohms or less?
Yes
SERVICE Circuit 296 (W/P) for short to ground. REPLACE fuse 6 (15A). RESTORE vehicle. RETEST system.

No
GO to A6 .

 

A6 CHECK CIRCUIT 296 (W/P) FOR OPEN

  • Disconnect ohmmeter lead from ground and connect lead to output side of fuse 6 (15A).
  • Is resistance 5 ohms or less?
Yes
REPLACE fuse 6 (15A). RESTORE system. RETEST vehicle.

No
SERVICE Circuit 296 (W/P) for open circuit. RESTORE vehicle. RETEST system.

 

A7 CHECK FOR CHIME MODULE GROUND

  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 1, Circuit 57 (BK).
  • Check resistance.
  • Is resistance 5 ohms or less?
Yes
REPLACE warning chime module. RESTORE vehicle. RETEST system.

No
SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system.

  

PINPOINT TEST B: SAFETY BELT WARNING INOPERATIVE

 

B1 CHECK SAFETY BELT SWITCH INPUT  

  • Unbuckle driver safety belt.
  • Using an ohmmeter connected to a known good ground, connect second lead to Pin 2, Circuit 85 (BR/LB) at chime module connector.
  • Measure resistance.
  • Is resistance 5 ohms or less?
Yes
GO to B2 .

No
SERVICE Circuit 85 (BR/LB) for open circuit. RESTORE vehicle. RETEST system.

 

B2 CHECK CIRCUIT 450 (DG/LG) OUTPUT AT MODULE

  • Using a test lamp connected to a known good ground, connect test lamp probe to Pin 10, Circuit 450 (DG/LG) at chime module connector.
  • Turn ignition switch to the RUN position.
  • Did test lamp illuminate?
Yes
GO to B3 .

No
REPLACE warning chime module. RESTORE vehicle. RETEST system.

 

B3 CHECK CIRCUIT 450 (DG/LG) INPUT AT INSTRUMENT CLUSTER

  • Turn ignition switch off.
  • Connect test lamp probe to Pin 12, Circuit 450 (DG/LG) at instrument cluster connector.
  • Turn ignition switch to the RUN position.
  • Did test lamp illuminate?
Yes
REPLACE fasten belts indicator bulb. RESTORE vehicle. RETEST system.

No
GO to B4 .

 

B4 CHECK CIRCUIT 450 (DG/LG) FOR OPEN

  • Turn ignition switch off.
  • Disconnect safety belt warning chime .
  • Using an ohmmeter, connect one lead to Pin 10, Circuit 450 (DG/LG) at module connector. Connect second lead to Pin 12, Circuit 450 9DG/LG) at instrument cluster connector.
  • Check continuity.
  • Is resistance 5 ohms or less?
Yes
REPLACE fasten belts indicator bulb. RESTORE vehicle. RETEST system.

No
SERVICE Circuit 450 (DG/LG) for open circuit. RESTORE vehicle. RETEST system.

  

PINPOINT TEST C: KEY IN IGNITION WARNING INOPERATIVE

 

C1 CHECK KEY IN IGNITION INPUT  

  • Open driver door.
  • Using a jumper wire connected to a known good ground, connect other end of jumper to Pin 5, Circuit 158 (BK/PK) at warning module connector.
  • Did warning module chime?
Yes
GO to C2 .

No
REPLACE chime module. RESTORE vehicle. RETEST system.

 

C2 CHECK CIRCUIT 158 (BK/PK) FOR OPEN

  • Disconnect chime module.
  • Disconnect key in ignition switch at steering column.
  • Using an ohmmeter, connect one lead to Pin 5, Circuit 158 (BK/PK) at module connector. Connect second lead to Circuit 158 (BK/PK) at key in ignition switch connector.
  • Check continuity.
  • Is there continuity?
Yes
REPLACE key in ignition switch . RESTORE vehicle. RETEST system.

No
SERVICE Circuit 158 (BK/PK) for open circuit. RESTORE vehicle. RETEST system.

  

PINPOINT TEST D: HEADLAMP ON WARNING INOPERATIVE

 

D1 CHECK DRIVER DOOR INPUT 

  • Open driver door.
  • Using a test lamp connected to a known good ground, connect probe end of test lamp to Pin 7, Circuit 159 (R/PK) at module connector.
  • Did test lamp illuminate?
Yes
GO to D2 .

No
SERVICE Circuit 159 (R/PK) for open circuit. RESTORE vehicle. RETEST system.

 

D2 CHECK HEADLAMP ON INPUT

  • Actuate headlamp switch to the park light position.
  • Connect test lamp probe to Pin 6, Circuit 14 (BR) at module connector.
  • Did test lamp illuminate?
Yes
REPLACE warning chime module. RESTORE vehicle. RETEST system.

No
GO to D3 .

 

D3 CHECK HEADLAMP SWITCH OUTPUT

  • Connect test lamp probe to Pin 12, Circuit 14 (BR) at headlamp switch.
  • Did test lamp illuminate?
Yes
SERVICE Circuit 14 (BR) for open circuit. RESTORE vehicle. RETEST system.

No
REPLACE headlamp switch . RESTORE vehicle. RETEST system.