1996 Bronco/F-Series

Section 13-09: Gauges/Warning Devices, Chime/Buzzer System

1996 F-150, F-250, F-350, F-Super Duty Chassis Cab Workshop Manual

DIAGNOSIS AND TESTING

Pinpoint Tests

Equipment: 12-volt test lamp or Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent.

When necessary to trace and/or service the circuits, refer to the appropriate electrical schematics.

The following is a step-by-step process of elimination procedure that must be performed in sequence in its entirety in order to obtain reliable results. If a specific failure condition is known, you may refer instead to the Bronco or F-Series Electrical and Vacuum Troubleshooting Manual to perform a quick check to determine cause and corrective action.

PINPOINT TEST A: WARNING CHIME/BUZZER INOPERATIVE

A1 CHECK FOR SUPPLY VOLTAGE

Key to RUN.
Connect a test lamp to a known good ground.
Connect probe end of test lamp to Pin 7, Circuit 640 (R/Y) at warning chime/buzzer module connector.

Did test lamp illuminate?

Yes	No
GO to A4.	GO to A2.

A2 CHECK SUPPLY CIRCUIT 640 (R/Y)

Key off.
Disconnect warning chime/buzzer module.
Using an ohmmeter connected to a known good ground, connect second lead to Pin 7, Circuit 640 (R/Y).
Check for continuity.

Is continuity present?

Yes	No
SERVICE Circuit 640 (R/Y) for short to ground. REPLACE fuse 17 (10A) (fuse 4 [15A] on motorhome) in IP fuse panel. RESTORE vehicle. RETEST system.	GO to A3.

A3 CHECK CIRCUIT 640 (R/Y) FOR OPEN

Disconnect ohmmeter lead from ground and connect lead to output side of fuse 17 (10A) (fuse 4 [15A] for motorhome) in IP fuse panel.
Check for continuity.

Is continuity present?

Yes	No
SERVICE power feed to fuse 17 (10A) (fuse 4 [15A] on motorhome) for open. RESTORE vehicle. RETEST system.	SERVICE Circuit 640 (R/Y) for open. RESTORE vehicle. RETEST system.

A4 CHECK WARNING CHIME/BUZZER MODULE GROUND

Using an ohmmeter connected to a known good ground, connect second lead to Pin 5, Circuit 57 (BK).
Check for continuity.

Is continuity present?

Yes	No
REPLACE warning chime/buzzer module. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open. RESTORE vehicle. RETEST system.

PINPOINT TEST B: SAFETY BELT WARNING INOPERATIVE

B1 CHECK SAFETY BELT SWITCH INPUT

Unbuckle driver safety belt.
Disconnect warning chime/buzzer module connector.
Using an ohmmeter connected to a known good ground, connect second lead to Pin 3, Circuit 85 (BR/LB) at warning chime/buzzer module connector.
Check for continuity.

Is continuity present?

Yes	No
GO to B2.	GO to B5.

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

Reconnect warning chime/buzzer module connector.
Using a test lamp connected to a known good ground, connect test lamp probe to Pin 6, Circuit 450 (DG/LG) at warning chime/buzzer module connector.
Key to RUN.

Does test lamp illuminate?

Yes	No
GO to B3.	REPLACE warning chime/buzzer module. RESTORE vehicle. RETEST system.

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

Key off.
Connect test lamp probe to Pin 4, Circuit 450 (DG/LG) at instrument cluster connector C1.
Key to RUN.

Does test lamp illuminate?

Yes	No
GO to B6.	GO to B4.

B4 CHECK CIRCUIT 450 (DG/LG) FOR OPEN

Key off.
Disconnect warning chime/buzzer module connector.
Using an ohmmeter, connect one lead to Pin 6, Circuit 450 (DG/LG) at warning chime/buzzer module connector. Connect second lead to Pin 4, Circuit 450 (DG/LG) at instrument cluster connector C1.
Check for continuity.

Is continuity present?

Yes	No
GO to B6.	SERVICE Circuit 450 (DG/LG) for open. RESTORE vehicle. RETEST system.

B5 CHECK SAFETY BELT BUCKLE SWITCH CIRCUIT 57 (BK) FOR OPEN

Disconnect driver safety belt buckle switch.
Check for continuity between harness connector Circuit 57 (BK) and known good ground.

Is continuity present?

Yes	No
SERVICE or REPLACE safety belt buckle switch. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open. RESTORE vehicle. RETEST system.

B6 CHECK INSTRUMENT CLUSTER CIRCUIT 57 (BK) FOR OPEN

Remove instrument cluster from instrument panel. Refer to Removal and Installation in Section 13-01.
Disconnect instrument cluster connector C1.
Check instrument cluster connector Circuit 57 (BK), Pin 3 for continuity to known good ground.

Is continuity present?

Yes	No
GO to B7.	SERVICE Circuit 57 (BK) for open. RESTORE vehicle. RETEST system.

B7 CHECK BULB

Remove safety belt indicator bulb. Refer to Removal and Installation in Section 13-00.
Check bulb for continuity.

Is bulb OK?

Yes	No
SERVICE instrument cluster printed circuit for open or REPLACE as required. RESTORE vehicle. RETEST system.	REPLACE fasten belts indicator bulb. 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 4, Circuit 158 (BK/PK) at warning chime/buzzer module connector.

Does warning chime/buzzer module sound?

Yes	No
GO to C2.	GO to C3.

C2 CHECK CIRCUIT 158 (BK/PK) FOR OPEN

Disconnect warning chime/buzzer module.
Disconnect key-in-ignition switch at steering column.
Using an ohmmeter, connect one lead to Pin 4, Circuit 158 (BK/PK) at warning chime/buzzer module connector. Connect second lead to Circuit 158 (BK/PK) at key-in-ignition switch connector.
Check for continuity.

Is continuity present?

Yes	No
REPLACE key-in-ignition switch. RESTORE vehicle. RETEST system.	SERVICE Circuit 158 (BK/PK) for open. RESTORE vehicle. RETEST system.

C3 CHECK CIRCUIT 159 (R/PK) FOR BATTERY VOLTAGE

Disconnect warning chime/buzzer module connector.
Check Pin 2 for battery voltage.

Is battery voltage present?

Yes	No
REPLACE warning chime/buzzer module. RESTORE vehicle. RETEST system.	GO to C4.

C4 CHECK CIRCUIT 54 (LB/Y) FOR BATTERY VOLTAGE

Disconnect driver door courtesy lamp switch.
Check for battery voltage on Circuit 54 (LG/Y) of harness connector.

Is battery voltage present?

Yes	No
REPLACE driver door courtesy lamp switch. RESTORE vehicle. RETEST system.	GO to C5.

C5 CHECK CIRCUIT 54 (LG/Y) FOR OPEN

Remove fuse 8 (15A) from IP fuse panel.
Check Circuit 54 (LG/Y) for continuity between fuse 8 (15A) output cavity and driver door courtesy lamp switch connector.

Is continuity present?

Yes	No
CHECK fuse 8 (15A) in IP fuse panel and fuse 20 (60A) in power distribution box for continuity. REPLACE as required. If fuses are OK, SERVICE Circuit 38 (BK/O) for open. RESTORE vehicle. RETEST system.	SERVICE Circuit 54 (LG/Y) for open. 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 2, Circuit 159 (R/PK) at warning chime/buzzer module connector.

Does test lamp illuminate?

Yes	No
GO to D2.	GO to D6.

D2 CHECK HEADLAMP-ON INPUT

Actuate headlamp switch to the PARK position.
Connect test lamp probe to Pin 1, Circuit 14 (BR) at warning chime/buzzer module connector.

Does test lamp illuminate?

Yes	No
GO to D4.	GO to D3.

D3 CHECK HEADLAMP SWITCH OUTPUT

Connect test lamp probe to Pin R, Circuit 14 (BR) at headlamp switch connector.

Does test lamp illuminate?

Yes	No
SERVICE Circuit 14 (BR) for open. RESTORE vehicle. RETEST system.	GO to D5.

D4 CHECK CIRCUIT 57 (BK) FOR OPEN

Disconnect warning chime/buzzer module connector.
Using an ohmmeter, check for continuity between warning chime/buzzer module connector Pin 5 and known good ground.

Is continuity present?

Yes	No
REPLACE warning chime/buzzer module. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open. RESTORE vehicle. RETEST system.

D5 CHECK HEADLAMP SWITCH POWER FEED

Disconnect headlamp switch connector.
Using a test lamp connected to known good ground, connect test lamp probe to headlamp switch connector Pin B2, Circuit 195 (T/W).

Does test lamp illuminate?

Yes	No
REPLACE headlamp switch. RESTORE vehicle. RETEST system.	GO to Diagnosis and Testing in Section 17-01 for headlamp switch power feed fault.

D6 CHECK CIRCUIT 54 (LG/Y) FOR BATTERY VOLTAGE

Gain access to driver door courtesy lamp switch.
Using a test lamp connected to a known good ground, connect probe end of test lamp to Circuit 54 (LG/Y) of courtesy lamp switch.

Does test lamp illuminate?

Yes	No
GO to D7.	GO to D8.

D7 CHECK CIRCUIT 159 (R/PK) FOR OPEN

Disconnect warning chime/buzzer module connector.
Disconnect driver door courtesy lamp switch connector.
Using an ohmmeter, check for continuity between warning chime/buzzer module connector Pin 2 and Circuit 159 (R/BK) on courtesy lamp switch connector.

Is continuity present?

Yes	No
REPLACE courtesy lamp switch. RESTORE vehicle. RETEST system.	SERVICE Circuit 159 (R/PK) for open. RESTORE vehicle. RETEST system.

D8 CHECK CIRCUIT 54 (LG/Y) FOR OPEN

Remove fuse 8 (15A) from IP fuse panel.
Check Circuit 54 (LG/Y) for continuity between fuse 8 (15A) output cavity and driver door courtesy lamp switch connector.

Is continuity present?

Yes	No
SERVICE power feed to fuse 8 (15A) for open. RESTORE vehicle. RETEST system.	SERVICE Circuit 54 (LG/Y) for open. RESTORE vehicle. RETEST system.