Dodge RAM TRUCK 1500 1995 Service Manual page 369

80 - 2 OVERHEAD CONSOLE
D I A G N O S I S
COMPASS/THERMOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES
OVERHEAD CONSOLE
DISPLAY COMPLETELY
DARK
1. Display has been switched off.
2. Faulty fuse or headlamp delay
module.
3. Faulty wiring.
4. Faulty compass/thermometer
display module.
1. Depress COMP/TEMP button to switch
unit to compass or thermometer display
option.
2. Refer to Group 8L — Lamps, for
diagnosis and service of this circuit.
3. Refer to Group 8W — Wiring Diagrams,
for circuit diagrams. Check and repair
wiring, if required.
4. Replace compass/thermometer display
module, if required.
OVERHEAD CONSOLE
DISPLAY S E G M E N T S
MISSING
1. Faulty compass/thermometer
display module.
1. See Self-Diagnostic Test, in this group.
Replace compass/thermometer display
module, if required.
ERRATIC C O M P A S S
OPERATION
1. Magnet or strong magnetic field
near compass module.
2. Variance setting incorrect.
3. Calibration incorrect.
4. Faulty compass/thermometer
display module.
1. Remove magnet and perform
Demagnetizing Procedure, in this group.
2. See Variation Adjustment Procedure in
this group.
3. See Calibration Procedure, in this group.
4. Replace compass/thermometer display
module, if required.
ERRATIC T H E R M O M E T E R
OPERATION
1. Faulty sensor wiring.
2. Faulty sensor.
3. Faulty compass/thermometer
display module.
1. See Sensor Circuit Test, in this group.
Repair wiring, if required.
2. See Sensor Test, in this group. Replace
sensor, if required.
3. Replace compass/thermometer display
module, if required.
J958C-1
COMPASS/DISPLAY SELF-DIAGNOSTIC TEST
This self-diagnostic test is used to determine that
the compass and all of its display segments are oper­
ating properly electrically. Initiate the self-diagnostic
tests as follows:
(1) With the ignition switch in the OFF position,
simultaneously press and hold the COMP/TEMP but­
ton and the US/METRIC button.
(2) Turn ignition switch to ON position.
(3) Continue to hold both buttons until segments
on the display light. The module is now in self-diag-
nostic test mode.
The display will respond by cycling through the fol­
lowing characters:
© N
00
• NW 11
o
W 22
® SW
33
• S
44
• SE
55
• E 66
• NE
77
To repeat test, press the COMP/TEMP button.
Pressing the US/METRIC button will light every seg­
ment of the display for 2 seconds. To repeat test,
press the COMP/TEMP button. To exit self-diagnos­
tics mode, press the US/METRIC button. The module
will return to compass/thermometer mode.
If the compass functions, but accuracy is sus­
pect, it may be necessary to perform a variation
adjustment. This procedure allows the unit to
accommodate variations in the earth's mag­
netic field strength based on geographic loca­
t i o n .
See Compass Variation Adjustment, in this
group.
If the compass display has blanked out and
only CAL appears, demagnetizing may be nec-