Dodge Dakota (R1). Manual - part 312
HORN
DESCRIPTION
The dual electromagnetic diaphragm-type horns
are standard equipment on this model. Both horns
are mounted on a single bracket that is secured to
the front of the left vertical member of the radiator
support, just behind the radiator grille and forward
of the radiator. The high-note horn is connected in
parallel with the low-note horn. The horns are con-
nected to the vehicle electrical system through the
headlamp and dash wire harness. Each horn is
grounded through its wire harness connector and a
ground circuit to an eyelet terminal secured by a
ground screw located on the right front inner fender
behind the right headlamp, and receives battery cur-
rent through the closed contacts of the horn relay.
Both horns and the mounting bracket are serviced
as a single unit. The horns cannot be repaired or
adjusted and, if faulty or damaged, the entire horn
and bracket unit must be replaced.
OPERATION
Within the two halves of the molded plastic horn
housing are a flexible diaphragm, a plunger, an elec-
tromagnetic coil and a set of contact points. The dia-
phragm
is
secured
in
suspension
around
its
perimeter by the mating surfaces of the horn hous-
ing. The plunger is secured to the center of the dia-
phragm
and
extends
into
the
center
of
the
electromagnetic coil. The contact points control the
current flow through the electromagnet.
When the horn is energized, electrical current
flows through the closed contact points to the electro-
magnet. The resulting electromagnetic field draws
the plunger and diaphragm toward it until that
movement mechanically opens the contact points.
When the contact points open, the electromagnetic
field collapses allowing the plunger and diaphragm to
return to their relaxed positions and closing the con-
tact points again. This cycle continues repeating at a
very rapid rate producing the vibration and move-
ment of air that creates the sound that is directed
through the horn outlet.
DIAGNOSIS AND TESTING - HORN
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds.
(1) Disconnect the wire harness connector(s) from
the horn connector receptacle(s). Measure the resis-
tance between the ground circuit cavity of the horn(s)
wire harness connector(s) and a good ground. There
should be no measurable resistance. If OK, go to Step
2. If not OK, repair the open ground circuit to ground
as required.
(2) Check for battery voltage at the horn relay out-
put circuit cavity of the horn(s) wire harness connec-
tor(s). There should be zero volts. If OK, go to Step 3.
If not OK, repair the shorted horn relay output cir-
cuit or replace the faulty horn relay as required.
(3) Depress the horn switch. There should now be
battery voltage at the horn relay output circuit cavity
of the horn(s) wire harness connector(s). If OK,
replace the faulty horn(s). If not OK, repair the open
horn relay output circuit to the horn relay as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the headlamp and dash wire har-
ness connectors from the horn connector receptacles
(Fig. 1) .
(3) Remove the screw that secures the horn and
mounting bracket unit to the front of the left vertical
member of the radiator support.
(4) Remove the horn and mounting bracket unit
from the radiator support.
Fig. 1 Horns Remove/Install
1 - RADIATOR SUPPORT
2 - HEADLAMP AND DASH WIRE HARNESS
3 - LOW NOTE
4 - SCREW
5 - HORN AND BRACKET
6 - HIGH NOTE
8H - 2
HORN
AN