General Information; Description And Operation - Dodge ram truck 3500 1996 Service Manual

OVERHEAD CONSOLE SYSTEMS 8V - 1
O V E R H E A D C O N S O L E SYSTEMS
C O N T E N T S
page
GENERAL INFORMATION
INTRODUCTION 1
DESCRIPTION AND OPERATION
COMPASS 1
READING/COURTESY LAMPS 2
THERMOMETER 1
DIAGNOSIS AND TESTING
COMPASS/DISPLAY MODULE 2
THERMOMETER 2
SERVICE PROCEDURES
COMPASS CALIBRATION 4
page
COMPASS DEMAGNETIZING 5
COMPASS VARIATION ADJUSTMENT 4
REMOVAL AND INSTALLATION
COMPASS/THERMOMETER/DISPLAY
MODULE 6
OVERHEAD CONSOLE 5
READING/COURTESY LAMP BULBS 7
TEMPERATURE SENSOR 6
G E N E R A L I N F O R M A T I O N
INTRODUCTION
An overhead console featuring an electronic com­
pass and thermometer is an available factory-in­
stalled option on this model. Following are general
descriptions of the major components used in the
overhead console. Refer to 8W-49 Overhead Console
in Group 8W - Wiring Diagrams for complete circuit
descriptions and diagrams.
D E S C R I P T I O N A N D O P E R A T I O N
COMPASS
The compass will display the direction i n which the
vehicle is pointed using the eight major compass
headings (Examples: north is N , northeast is NE). I t
does not display the headings in actual degrees. The
display is turned on or off using the Comp/Temp but­
ton, located to the left of the display module.
The . self-calibrating compass unit requires no
adjusting i n normal use. The only calibration that
may prove necessary is to drive the vehicle in three
complete circles, on level ground, in not less than 48
seconds. This will reorient the compass unit to its
vehicle.
The compass unit also will compensate for magne­
tism the body of the vehicle may acquire during nor­
mal use. However, avoid placing anything magnetic
directly on the roof of the vehicle. Magnetic mounts
for an antenna, a repair order hat, or a funeral pro­
cession flag can exceed the compensating ability of
the compass unit i f placed on the roof panel. Mag­
netic bit drivers used on the fasteners that hold the
assembly to the roof header can also affect compass
operation. I f the vehicle roof should become magne­
tized, the demagnetizing and calibration procedures
found in this group may be required to restore proper
compass operation.
The compass, thermometer, and display module
cannot be repaired, and are only available for service
as a unit. I f faulty, the complete assembly must be
replaced.
THERMOMETER
The thermometer displays the outside ambient
temperature. The temperature display can be
changed from Fahrenheit to, Celsius using the
US/Metric button, located to the right of the display
module. The displayed temperature is not an instant
reading of conditions, but an average temperature. I t
may take the thermometer display several minutes
to respond to a major temperature change, such as
driving out of a heated garage into winter tempera­
tures.
When the ignition switch is turned to the Off posi­
tion, the last displayed temperature reading stays i n
the thermometer unit memory. When the ignition
switch is turned to the On position again, the ther­
mometer will display the memory temperature for
one minute; then update the display to the current
average temperature reading within five minutes.
The thermometer function is supported by an
ambient temperature sensor. The sensor is mounted
outside the passenger compartment near the front
and center of the vehicle. The ambient temperature
sensor is available as a separate service item.
The compass, thermometer, and display module
cannot be repaired, and are only available for service