1996 Bronco/F-Series

Section 17-01: Lighting, Exterior

1996 F-150, F-250, F-350, F-Super Duty Motorhome and Bronco Workshop Manual

DIAGNOSIS AND TESTING

Pinpoint Tests — Parking Lamps

NOTE: Use Rotunda 73 Digital Multimeter 105-R0051 or equivalent when performing electrical pinpoint tests.

PINPOINT TEST R: PARKING LAMPS INOPERATIVE

R1 CHECK CIRCUIT 14 (BR) AT HEADLAMP SWITCH

Actuate headlamp switch to the PARK position.
Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, check Circuit 14 (BR) at headlamp switch Pin R for voltage.

Is battery voltage present?

Yes	No
SERVICE Circuit 14 (BR) for an open circuit. RESTORE vehicle. RETEST system.	GO to R2.

R2 CHECK SUPPLY TO PARKING LAMPS

With Rotunda 73 Digital Multimeter 105-R0051 or equivalent, check for voltage on Circuit 195 (T/W) at headlamp switch.

Is battery voltage present?

Yes	No
REPLACE damaged headlamp switch. RESTORE vehicle. RETEST system.	GO to R3.

R3 CHECK SUPPLY CIRCUIT TO HEADLAMP SWITCH

Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, check Circuit 195 (T/W) at output side of IP fuse 4 (15A).

Is battery voltage present?

Yes	No
SERVICE Circuit 195 (T/W) for an open circuit. RESTORE vehicle. RETEST system.	GO to R4.

R4 CHECK IP FUSE 4

Remove and inspect IP fuse panel fuse 4, 15A for an open circuit.

Is fuse 4 good?

Yes	No
GO to R5.	REPLACE fuse 4. REPEAT step R4.

R5 CHECK SUPPLY TO FUSE 4

Using a Rotunda 73 Digital Multimeter 105-R0051 or equivalent, check for voltage at feed side of IP fuse 4, Circuit 38 (BK/O) and load side of power distribution box fuse 20, 50A, Circuit 38 (BK/O).

Is battery voltage present?

Yes	No
GO to R6.	REPAIR open in Circuit 38 (BK/O). RESTORE vehicle. RETEST system.

R6 CHECK POWER DISTRIBUTION BOX FUSE 20

Remove and inspect power distribution box fuse 20, 50A for an open circuit.

Is fuse 20 good?

Yes	No
REPAIR power distribution box power feed, Circuit 37 (Y). RESTORE vehicle. RETEST system.	REPLACE fuse 20, 50A. RESTORE vehicle. RETEST system.

PINPOINT TEST S: ONE OR MORE PARKING LAMPS INOPERATIVE

S1 CHECK SUPPLY TO SUSPECT PARKING LAMP

Turn headlamp switch to the parking lamp position.
Gain access to suspect parking lamp connector. Disconnect the suspect parking lamp.
Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, connect the other end to Circuit 14 (BR) at parking lamp connector.

Is battery voltage present?

Yes	No
GO to S2.	SERVICE Circuit 14 (BR) for an open circuit. RESTORE vehicle. RETEST system.

S2 CHECK SUSPECT PARKING LAMP

Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, connect second lead to Circuit 57 (BK) at suspect park lamp connector.
Measure resistance.

Is resistance 5 ohms or less?

Yes	No
REPLACE damaged park lamp miniature bulb. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system.

PINPOINT TEST T: PARKING LAMPS ON CONTINUOUSLY

T1 CHECK HEADLAMP SWITCH HARNESS

Disconnect battery ground cable.
Remove headlamp switch harness from the headlamp switch.
Reattach the battery ground cable.

Do the parking lights go on?

Yes	No
REPAIR short to power. RESTORE vehicle. RETEST system.	GO to T2.

T2 HEADLAMP SWITCH TEST

Disconnect the battery ground cable.
Reconnect the headlamp switch harness to the headlamp switch. Headlamp switch in OFF position.
Reattach the battery ground cable.

Do the parking lights go on?

Yes	No
REPLACE miniature bulb. RESTORE vehicle. RETEST system.	System OK.

PINPOINT TEST U: ONE OR MORE SIDE MARKER LAMPS INOPERATIVE

U1 CHECK VOLTAGE TO MARKER LAMPS

Turn headlamp switch to the ON position.
Gain access to the suspect marker lamp connector.
Disconnect the marker lamp bulb.
Using a Rotunda 73 Digital Multimeter 105-R0051 or equivalent, probe Circuit 667 (W/R) for voltage.

Is battery voltage present?

Yes	No
GO to U2.	SERVICE Circuit 667 (W/R) for an open circuit. RESTORE vehicle. RETEST system.

U2 CHECK SIDE MARKER LAMP GROUND

Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, connect the second lead to Circuit 206 (W) at the marker connector.
Measure the resistance.

Is the resistance 5 ohms or less?

Yes	No
REPLACE damaged marker lamp miniature bulb. RESTORE vehicle. RETEST system.	SERVICE Circuit 206 (W) for open circuit. RESTORE vehicle. RETEST system.

PINPOINT TEST V: ONE OR MORE TAIL LAMPS INOPERATIVE

V1 CHECK VOLTAGE TO TAIL LAMPS

Turn headlamp switch to the ON position.
Gain access to the suspect tail lamp connector.
Disconnect the suspect tail lamp.
Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent, probe for voltage on Circuit 14 (BR) at the tail lamp.

Is battery voltage present?

Yes	No
GO to V2.	SERVICE Circuit 14 (BR) for an open circuit. RESTORE vehicle. RETEST system.

V2 CHECK TAIL LAMP GROUND

Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, connect the second lead to Circuit 57 (BK) at the tail lamp connector.
Measure the resistance.

Is the resistance 5 ohms or less?

Yes	No
REPLACE damaged tail lamp miniature bulb. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system.

PINPOINT TEST W: ONE OR MORE LICENSE LAMPS INOPERATIVE

W1 CHECK VOLTAGE TO TAIL LAMPS

Turn headlamp switch to the ON position.
Gain access to the suspect license lamp connector.
Disconnect the license lamp bulb.
Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent, probe for voltage on Circuit 14 (BR) at the license lamp.

Is battery voltage present?

Yes	No
GO to W2.	SERVICE Circuit 14 (BR) for an open circuit. RESTORE vehicle. RETEST system.

W2 CHECK LICENSE LAMP GROUND

Using Rotunda 73 Digital Multimeter 105-R0051 or equivalent connected to a known good ground, connect the second lead to Circuit 57 (BK) at the license lamp connector.
Measure the resistance.

Is the resistance 5 ohms or less?

Yes	No
REPLACE damaged license lamp miniature bulb. RESTORE vehicle. RETEST system.	SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system.