Horn Switch Diagnosis And Testing; Horn Diagnosis And Testing; Horn Relay Removal And Installation - Jeep Cherokee 2000 Service Manual

8G - 4 HORN SYSTEMS
DIAGNOSIS AND TESTING (Continued)
HORN SWITCH
For complete circuit diagrams, refer to Horn/Ci-
gar Lighter in the Contents of Group 8W - Wiring
Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO
RESTRAINT SYSTEMS BEFORE ATTEMPTING ANY
STEERING WHEEL,
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable. Remove the knee blocker from the instrument
panel.
(2) Check for continuity between the metal steer-
ing column jacket and a good ground. There should
be continuity. If OK, go to Step 3. If not OK, refer to
Steering Column in the Removal and Installation
section of Group 19 - Steering for proper installation
of the steering column.
(3) Remove the driver side airbag module from the
steering wheel. Disconnect the horn switch wire har-
ness connectors from the driver side airbag module.
(4) Remove the horn relay from the junction block.
Check for continuity between the steering column
half of the horn switch feed wire harness connector
and a good ground. There should be no continuity. If
OK, go to Step 5. If not OK, repair the shorted horn
relay control circuit to the horn relay in the junction
block as required.
(5) Check for continuity between the steering col-
umn half of the horn switch feed wire harness con-
nector and the horn relay control circuit cavity for
the horn relay in the junction block. There should be
continuity. If OK, go to Step 6. If not OK, repair the
open horn relay control circuit to the horn relay in
the junction block as required.
(6) Check for continuity between the horn switch
feed wire and the horn switch ground wire on the
driver side airbag module. There should be no conti-
nuity. If OK, go to Step 7. If not OK, replace the
faulty horn switch.
(7) Depress the center of the driver side airbag
module trim cover and check for continuity between
the horn switch feed wire and the horn switch
ground wire on the driver side airbag module. There
should now be continuity. If not OK, replace the
faulty horn switch.
GROUP 8M - PASSIVE
STEERING COLUMN,
HORN
For complete circuit diagrams, refer to Horn/Ci-
gar Lighter in the Contents of Group 8W - Wiring
Diagrams.
(1) Measure the resistance between the horn(s)
mounting bracket(s) and a good ground. There should
be no measurable resistance. If OK, go to Step 2. If
not OK, clean and tighten the horn mounting hard-
OR
ware as required.
(2) Disconnect the wire harness connector(s) from
the horn connector receptacle(s). Check for battery
voltage at the horn relay output circuit cavity of the
horn(s) wire harness connector(s). There should be
zero volts. If OK, go to Step 3. If not OK, repair the
shorted horn relay output circuit 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 AND INSTALLATION
HORN RELAY
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the fuse access panel by unsnapping it
from the right cowl side inner trim panel (Fig. 3).
(3) Remove the push nut that secures the right
cowl side inner trim panel to the junction block stud.
(4) Remove the screw located above the fuse access
opening that secures the trim panel to the right cowl
side inner panel.
(5) Remove the screw that secures the right cowl
side inner trim panel and right front door sill trim to
the door opening sill.
(6) Remove the trim from the right cowl side inner
panel.
(7) Refer to Junction Block in the Contents of
Group 8W - Wiring Diagrams for horn relay identifi-
cation and location.
(8) Remove the horn relay from the junction block.
INSTALLATION
(1) Refer to Junction Block in the Contents of
Group 8W - Wiring Diagrams for proper horn relay
location.
(2) Position the horn relay in the proper receptacle
in the junction block.
(3) Align the horn relay terminals with the termi-
nal cavities in the junction block receptacle.
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