1996 Bronco/F-Series

Section 01-09: Mirrors, Rearview

1996 F-150, F-250, F-350 and Bronco Workshop Manual

DIAGNOSIS AND TESTING

Pinpoint Tests

NOTE: Use Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent to perform electrical pinpoint tests.

PINPOINT TEST A: BOTH RH AND LH MIRRORS INOPERATIVE

A1 FUSE CHECK

Check fuse in panel.

Is fuse in panel OK?

Yes	No
REMOVE outside rear view mirror control. CHECK for power across Circuit 54 (LG/Y). REPLACE outside rear view mirror control. GO to A2.	REPLACE fuse.

A2 CONTINUITY CHECK

Check continuity in wire harness circuits.

Is continuity OK?

Yes	No
REMOVE front door trim panel. CHECK harness connector to outside rear view mirror. REPLACE outside rear view mirror.	CHECK continuity of circuits. TRACE continuity to connector. REPLACE mirror. GO to A3.

A3 CIRCUIT LOGIC CHECK

Check circuit logic at outside mirror control wiring connector.

Is circuit logic at harness connector to outside rear view mirror with outside rear view mirror control operating OK?

Yes	No
REPLACE outside rear view mirror.	CHECK circuit continuity in outside mirror control wiring to outside rear view mirror with outside rear view mirror control operational. CHECK connector. TRACE along outside mirror control wiring to determine cross circuitry location and connect.

PINPOINT TEST B: SINGLE MIRROR INOPERATIVE

B1 VERIFY THAT HARNESS IS CONNECTED TO MIRROR

Remove front door trim panel and verify that outside mirror control wiring is connected. Refer to Section 01-05.

Is harness connected?

Yes	No
GO to B2.	CHECK outside mirror control wiring connector for damage and reconnect. CHECK outside rear view mirror for proper operation.

B2 CHECK CONTINUITY OF CIRCUITS IN HARNESS CONNECTOR

Check continuity of Circuits 540 (R), 541 (DB) and 542 (Y) for left outside rear view mirror, or Circuits 542 (Y), 543 (DG) and 544 (P) for right outside rear view mirror, in outside mirror control wiring connector to outside rear view mirror by operating outside rear view mirror control.

Do circuits have continuity?

Yes	No
REPLACE the outside rearview mirror motor (if serviced) or outside rear view mirror.	Using Power Mirror Logic Table located in this section, TRACE circuits to connector and SERVICE as required.

PINPOINT TEST C: SINGLE MIRROR DOES NOT FUNCTION WITH SWITCH LOGIC

C1 VERIFY CIRCUIT LOGIC AT HARNESS CONNECTOR TO MIRROR

Using a putty knife, pry the mirror switch up and out of the bezel.
Verify circuit logic at harness connector to outside rear view mirror with switch operation. Refer to Power Mirror Logic Table in this section.

Does outside rear view mirror control operate properly?

Yes	No
REPLACE outside rearview mirror motor kit.	GO to C2.

C2 CHECK CIRCUIT LOGIC AT SWITCH CONNECTOR

Verify circuit logic at switch connector. Refer to Power Mirror Logic Table in this section.

Is circuit logic OK at outside rear view mirror control?

Yes	No
TRACE along outside mirror control wiring to determine where cross circuitry took place. SERVICE as required.	REPLACE outside rear view mirror control and RETEST mirror operation.

PINPOINT TEST D: AUTOMATIC DIMMING OUTSIDE/INSIDE MIRROR DOES NOT SWITCH AUTOMATICALLY

D1 CHECK MIRROR OPERATION

Cover the sensor on the backside of the inside rear view mirror with a dark (preferably black) cloth.

With a flashlight, shine light on the sensor located in the center of the mirror glass.

Does the mirror glass darken to the non-reflective state?

Yes	No
Inside rear view mirror checks OK.	GO to D2.

D2 CHECK FOR BACKUP SIGNAL

Check for backup signal between Circuit 57 (BK) and Circuit 140 (BK/PK) at connector.

Is there a signal?

Yes	No
GO to D4.	GO to D3.

D3 CHECK CIRCUIT 140 (BK/PK)

Check for ground short or open in Circuit 140 (BK/PK) between electronic day/night mirror connector and backup lamp switch.

Does circuit check OK?

Yes	No
CHECK backup lamp switch for damage or wear. REPLACE switch. GO to D4.	CHECK for loose connectors or short to ground in Circuit 140 (BK/PK). SERVICE as required.

D4 CHECK FOR A BLOWN FUSE

Is the fuse blown?

Yes	No
REPLACE and RETEST the inside rear view mirror for correct operation.	GO to D5.

D5 CHECK FOR VOLTAGE BETWEEN CIRCUITS 296 (W/P) AND 57 (BK)

Remove electrical connector from rear of inside rear view mirror.
Check for voltage at the feed connector of the inside rearview mirror connector.

With key in RUN, is voltage present between Circuit 296 (W/P) and Circuit 57 (B/K)?

Yes	No
Carefully and securely PLUG inside rear view mirror feed connector into back of inside rear view mirror and again CHECK for correct operation.	GO to D6.

D6 CHECK ACROSS CIRCUIT 296 (W/P) TO A KNOWN GOOD GROUND

Check for voltage between Circuit 296 (W/P) and a good ground.

Is there voltage?

Yes	No
SERVICE Circuit 57 (BK) as required. GO to D7.	SERVICE Circuit 296 (W/P) as required. GO to D7.

D7 RETEST MIRROR OPERATION

Reconnect inside rear view mirror.
Check inside rear view mirror. Refer to Test Step D1.

Does mirror glass darken to the nonreflective state?

Yes	No
Inside rear view mirror checks OK.	REPLACE inside rear view mirror.