1996 Bronco/F-Series

Section 13-07: Compass/Outside Temperature Display

1996 Eddie Bauer Bronco Workshop Manual

DIAGNOSIS AND TESTING

Pinpoint Tests

PINPOINT TEST A: COMPASS READING IS INACCURATE

A1 DISPLAY PROVEOUT

Key to RUN.
Verify that following display actions occurred in order:

All segments light for approximately one second.
All segments go blank for approximately one second.
Compass then displays directional heading.

Is display functioning correctly?

Yes	No
GO to A3.	If compass display does not light, GO to A2. If some segments do not light, REPLACE compass and thermometer. If some segments do not turn off, REPLACE compass and thermometer. If directional heading is not displayed, DEMAGNETIZE vehicle. If directional heading is displayed, GO to A2. If CAL is shown on display, slowly DRIVE in circles until CAL is NOT lit. If, after three circles, CAL is still lit, DEMAGNETIZE and DRIVE in circles again. After three circles DEMAGNETIZE and DRIVE in circles again.

Yes

GO to A3.

If compass display does not light, GO to A2.

If some segments do not light, REPLACE compass and thermometer.

If some segments do not turn off, REPLACE compass and thermometer.

If directional heading is not displayed, DEMAGNETIZE vehicle.

If directional heading is displayed, GO to A2.

If CAL is shown on display, slowly DRIVE in circles until CAL is NOT lit. If, after three circles, CAL is still lit, DEMAGNETIZE and DRIVE in circles again. After three circles DEMAGNETIZE and DRIVE in circles again.

A2 DIMMING CIRCUIT CHECK

Pull and rotate headlamp dimmer switch.

Does compass display dim correspondingly with instrument panel illumination lamps?

Yes	No
GO to A3.	GO to A5. If compass display goes blank, REPLACE compass and thermometer. RETEST system.

A3 COMPASS ACCURACY CHECK

Perform compass Calibration Procedure and Zone Adjustment.
Observe and record compass switch points while driving vehicle in a circle.
Verify that each compass heading quadrant is greater than 35 degrees and less than 55 degrees wide.

Is compass accurate?

Yes	No
GO to A4.	PERFORM Vehicle Demagnetizing procedure. REPEAT Calibration Procedure and Zone Adjustment. If compass still is not accurate, REPLACE compass. RETEST system.

A4 POWER SUPPLY CHECK

Remove one screw retaining overhead console to roof.
Disconnect the 10-pin connector.
Key to RUN.
Using Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent, verify battery voltage on Pin 8, Circuit 296 (W/P).

Is battery voltage present?

Yes	No
REPLACE compass and thermometer. RETEST system.	SERVICE wiring or ignition switch. RETEST system.

A5 VOLTAGE CHECK

Remove one screw retaining overhead console to roof.
Disconnect the 10-pin connector.
Key to RUN.
Using Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent, verify that voltage is present on Pin 3, Circuit 19 (LB/R) and that it varies as the dimmer rheostat is rotated.

Does voltage vary?

Yes	No
REPLACE compass and thermometer. RETEST system.	SERVICE wiring back to dimmer rheostat. RETEST system.

PINPOINT TEST B: TEMPERATURE DISPLAY INACCURATE

B1 SENSOR CIRCUIT TEST

Disconnect overhead console 10-pin connector and temperature sensor 2-pin connector.
Using Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent, verify continuity between 10-pin connector Pin 2, Circuit 233 (DB/Y) and 2-pin connector Circuit 233 (DB/Y).

Is continuity present?

Yes	No
GO to B2.	SERVICE Circuit 233 (DB/Y) for open. RETEST system.

B2 CONTINUITY CHECK

Using Rotunda Digital Volt-Ohmmeter 014-00407 or equivalent, verify continuity between 2-pin connector Circuit 767 (LB/O) at ambient sensor and compass/outside temperature module connector Pin 1.

Is continuity present?

Yes	No
REPLACE thermometer sensor. RETEST system.	SERVICE Circuit 767 (LB/O) for open. RETEST system.