Dodge ram truck 3500 1996 Service Manual page 455

BR
HORN SYSTEMS 8G - 1
HORN SYSTEMS
C O N T E N T S
page
GENERAL INFORMATION
INTRODUCTION 1
DESCRIPTION AND OPERATION
HORN RELAY . -1
HORN SWITCH 1
HORN 1
DIAGNOSIS AND TESTING
HORN RELAY 1
G E N E R A L I N F O R M A T I O N
INTRODUCTION
Following are general descriptions of the major
components in the factory-installed horn systems.
Refer to 8W-41 - Horns/Cigar Lighter 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
HORN RELAY
The horn relay is a International Standards Orga­
nization (ISO) micro-relay. The terminal designations
and functions are the same as a conventional ISO
relay. However, the micro-relay terminal orientation
(or footprint) is different, current capacity is lower,
and the relay case dimensions are smaller than on
the conventional ISO relay.
The horn relay is a electro-mechanical device that
switches current to the horn when the horn switch
on the steering wheel is depressed. See the Diagnosis
and Testing section of this group for more informa­
tion on the horn relay's operation.
The horn relay is located in the Power Distribution
Center (PDC) in the engine compartment. Refer to
the PDC label for horn relay identification and loca­
tion.
If a problem is encountered with a continuously
sounding horn, i t can usually be quickly resolved by
removing the horn relay from the PDC until further
diagnosis is completed.
HORN SWITCH
Two horn switches are installed in the steering
wheel, one on each side of the center-mounted driv­
er's airbag module. When either switch is depressed
it completes a circuit to ground for the coil side of the
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HORN SWITCH 2
HORN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
REMOVAL AND INSTALLATION
HORN RELAY 3
HORN SWITCH 3
HORN 4
horn relay. The steering wheel and steering column
must be properly grounded for the horn switches to
function. The horn switches are serviced only as a set
with their wiring. I f either switch should fail, both
switches must be replaced.
HORN
The standard single, low-note, diaphragm-type
horn is located on a bracket behind the left end of
the front bumper. I t is grounded through its wiring
connector and circuit to an eyelet near the power dis­
tribution center, and receives battery feed through
the closed contacts of the horn relay. I f the vehicle is
equipped with a dual horn option, a high-note, dia­
phragm-type horn is connected in parallel with, and
mounted next to, the standard low-note horn behind
the front bumper.
D I A G N O S I S A N D T E S T I N G
HORN RELAY
For circuit descriptions * and diagrams, refer to
8W-41 - Horns/Cigar Lighter in Group 8W - Wiring
Diagrams.
RELAY TESTS
The horn relay is located in the Power Distribution
Center (PDC) in the engine compartment. Refer to
the PDC label for horn relay identification and loca­
tion.
Remove the horn relay from the PDC as described
in this group to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. I f OK, go
to Step 2. I f not OK, replace the faulty relay.