Dodge RAM TRUCK 1500 1995 Service Manual page 450

HORNS
HORNS 8G - 1
C O N T E N T S
page page
DIAGNOSIS 1 SERVICE PROCEDURES 3
GENERAL INFORMATION 1
G E N E R A L I N F O R M A T I O N
Following are general descriptions of the major
components in the Ram truck horn system. Refer to
Group 8W - Wiring Diagrams for complete circuit de­
scriptions and diagrams.
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
horn relay. The steering wheel and steering column
must be properly grounded for the horn switches to
function. The horn switches are only serviced as a set
with their wiring. If either switch should fail, both
switches must be replaced.
HORN RELAY
The horn relay is installed in the Power Distribu­
tion Center (PDC) in the engine compartment near
the battery. One side of the horn relay electromag­
netic coil receives battery voltage at all times. When
a horn switch is depressed, the other side of the relay
coil is grounded. The energized relay coil causes the
normally open relay contacts to close, providing bat­
tery voltage to the horn.
If a problem is encountered with a continuously
sounding horn, it can usually be quickly resolved by
removing the horn relay from the PDC until further
diagnosis is completed.
HORN
The single, lo-note, diaphragm-type horn is located
on a bracket behind the left end of the front bumper.
It is grounded through its wiring connector and cir­
cuit to the horn bracket mounting bolt and receives
battery feed through the closed contacts of the horn
relay. The dual horn option adds a hi-note, dia­
phragm-type horn in the same location.
D I A G N O S I S
WARNING: B E F O R E BEGINNING ANY A I R B A G S Y S ­
TEM COMPONENT REMOVAL OR INSTALLATION,
REMOVE AND ISOLATE THE NEGATIVE (-) C A B L E
FROM THE BATTERY. THIS IS THE ONLY S U R E
WAY TO D I S A B L E THE A I R B A G S Y S T E M . FAILURE
TO DO THIS COULD R E S U L T IN ACCIDENTAL AIR-
B A G DEPLOYMENT AND P O S S I B L E INJURY. WAIT 2
MINUTES FOR THE A I R B A G S Y S T E M CAPACITOR
TO DISCHARGE B E F O R E REMOVING OR W O R K I N G
ON ANY A I R B A G S Y S T E M COMPONENTS.
HORN SYSTEM
(1) Inspect fuses B and 1 in PDC. If OK, go to next
step. If not OK, replace fuses as required.
(2) Remove the horn relay from the PDC. See Horn
Relay Connections (Fig. 1) and perform the following
tests:
(a) The common feed terminal (30) is connected
to battery voltage and should be hot at all times. If
battery voltage is not present at relay cavity 30,
check circuit to fuse B. Repair as required.
(b) The normally closed terminal (87A) is con­
nected to terminal 30 in the de-energized position,
but is not used for this application.
(c) The normally open terminal (87) is connected
to the common feed terminal (30) in the energized
position. This terminal supplies battery voltage to
the horn. There should be continuity between relay
cavity 87 and the horn feed terminal at all times. If
not, repair wiring or connections as required.