exj_8g99 jeep xj service manual

7/29/2019 EXJ_8G99 jeep xj service manual

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HORN SYSTEMS

CONTENTS

page page

GENERAL INFORMATIONINTRODUCTION . . . . . . . . . . . . . . . . . . . . . . . . 1

DESCRIPTION AND OPERATIONHORN RELAY . . . . . . . . . . . . . . . . . . . . . . . . . . 1HORN SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . 1HORN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1

DIAGNOSIS AND TESTING

HORN RELAY . . . . . . . . . . . . . . . . . . . . . . . . . . 2

HORN SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . 2HORN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

REMOVAL AND INSTALLATIONHORN RELAY . . . . . . . . . . . . . . . . . . . . . . . . . . 3HORN SWITCH . . . . . . . . . . . . . . . . . . . . . . . . . 4HORN . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

GENERAL INFORMATION

INTRODUCTIONF ol low i n g a r e g en er a l d es cr i pt i on s of t h e m a jor

com p on e n t s i n t h e f a c t or y -i n s t a l l ed h or n s y s t em s .

Refer t o 8W-41 - Horns/Ciga r Light er in G roup 8W -

Wi r in g Di a g r a m s f or com p le t e ci r cu i t d e scr i pt i on s

a n d d ia g r a m s .

NOTE: This group covers both Left-Hand Drive(LHD) and Right-Hand Drive (RHD) versions of thismodel. Whenever required and feasible, the RHD

versions of affected vehicle components have beenconstructed as mirror-image of the LHD versions.While most of the illustrations used in this group

represent only the LHD version, the diagnostic andservice procedures outlined can generally beapplied to either version. Exceptions to this rulehave been clearly identified as LHD or RHD, if aspecial illustration or procedure is required.

DESCRIPTION AND OPERATION

HORN RELAY

Th e h or n r e l a y i s a I n t e r n a t i o n a l St a n d a r d s O r g a -

nizat ion (ISO) relay. The r elay is a electromecha nical

d ev ice t h a t s w it ch es b a t t er y cu rr en t t o t h e h or nw h e n t h e h o r n s w i t ch g r ou n d s t h e r e la y coi l. S e e t h e

Dia gnosis an d Testing section of this group for more

information on the operation of the horn relay.

The horn relay is located in the junction block, on

the right cowl side panel below the instrument panel

i n t h e pa s sen ger com pa r t m en t . I f a p rob lem i s

e n cou n t e r ed w i t h a con t i n u ou s ly s ou n d i n g h or n , i t

can usually be quickly resolved by r emoving th e horn

relay from the junction block unti l further diagnosis

is completed.

The horn relay cannot be repaired and, i f faulty ord a m a g ed , i t m u s t be r e pl a c ed .

HORN SWITCH

A cen t e r-b low , r es is t iv e m em b ra n e t y p e h or n

switch is instal led on the back side of the driver side

a i r ba g m o d u l e t r i m c o v e r i n t h e c e n t e r o f t h e s t e e r -

i n g w h e el . Wh e n t h e ce n t er a r e a of t h e a i r ba g t r i m

cover is depressed, the horn sw itch completes a cir-

cuit to ground for the coil side of the horn relay. The

steering wheel and steering column must be properly

grounded for the horn switch to function.

Th e h o r n s w i t c h i s o n l y s e r vi ce d a s a p a r t of t h e

a i r ba g m o d u l e t r i m c o v e r . I f t h e h o r n s w i t c h s h o u l df a i l , o r i f t h e a i r ba g i s d e p l o y e d , t h e a i r ba g m o d u l e

t r i m c o v e r a n d h o r n s w i t c h u n i t m u s t be r e p l a c e d .

HORN

Dua l-note, electromagn etic dia phragm-type horns

a r e s t a n da r d eq u ipm en t . Th e l ow -n ot e h or n i s

m ou n t ed a n d g r ou n d ed t o t h e l ef t r a d i a t or cl os u re

panel brace, behind the front bumper. The high-note

horn is connected in parallel with the low-note horn.

The high-note horn is mounted and grounded to the

r i g h t r a d i a t o r cl os u r e p a n e l br a c e, beh i n d t h e f r on t

bumper. Both horns receive battery feed through the

closed contacts of the horn relay.Th e h o r n s c a n n o t be r e pa i r e d o r a d ju st e d a n d , i f

f a u l t y o r d a m a g e d , t h e y m u s t be r e p l a c e d .

NOTE: A cadmium-plated screw is used to mountthe horns. Do not substitute other types of screws,as they may become corroded and cause a loss ofhorn ground.

XJ H OR N SY STEM S 8 G - 1


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DIAGNOSIS AND TESTING

HORN RELAY

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o

8W-41 - H orns/Ciga r Light er in G roup 8W - Wiring

Di a g r a m s .

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO GROUP 8M - PASSIVE

RESTRAINT SYSTEMS BEFORE ATTEMPTING ANYSTEERING WHEEL, STEERING COLUMN, ORINSTRUMENT PANEL COMPONENT DIAGNOSIS ORSERVICE. FAILURE TO TAKE THE PROPER PRE-

CAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONALINJURY.

RELAY TEST

The horn relay is located in the junction block. Thejunction block is attached to the right cowl side inner

p a n el , b e low t h e i n st r u m en t p a n el a n d b eh i nd t h e

right cowl side trim panel .

Remove the horn relay from the junction block as

described in this group to perform the following tests:

(1) A r e l a y i n t h e d e -e n er g i ze d p os i t ion s h ou l d

h a v e c o n t i n u i t y be t w e e n t e r m i n a l s 8 7 A a n d 3 0 , a n d

no continuity between terminals 87 and 30. If OK, go

t o St e p 2 . I f n o t O K, r e p l a c e t h e f a u l t y r e l a y .

(2) Resistance between terminals 85 and 86 (elec-

tromagnet) should be 75 5 oh m s . I f O K, g o t o St e p

3 . I f n o t O K, r e p l a c e t h e f a u l t y r e l a y .

(3) C on n ect a b a t t er y t o t er m in a l s 85 a n d 86.Th e r e s h o u ld n ow be con t i n u i t y bet w e e n t e r m in a l s

30 and 87, and no continuity between terminals 87A

a n d 30. I f O K , s e e t h e R el a y C i r cu it Te st i n t h i s

g r o u p . I f n o t O K, r e p l a c e t h e f a u l t y r e l a y .

RELAY CIRCUIT TEST

(1) The relay common feed terminal cavity (30) is

con n e ct e d t o ba t t e r y v ol t a g e a n d s h ou l d be h o t a t a l l

t imes. If OK, go to Step 2. If not OK, repair the open

circuit to the fuse in the junction block as required.

(2) Th e r e la y n or m a l l y cl os ed t e r m in a l (87A) i s

connected to terminal 30 in the de-energized position,bu t i s n o t u s e d f o r t h i s a p p l i c a t i o n . Go t o St e p 3 .

(3) The relay normally open terminal (87) is con-

nected to the common feed terminal (30) in the ener-

gized position. This terminal supplies bat tery volta ge

to the horn(s). There should be continuity between

t h e c a v i t y f o r r e l a y t e r m i n a l 8 7 a n d t h e r e l a y o u t p u t

circuit cavity of each horn wire harness connector at

a l l t i m e s . I f O K , g o t o S t e p 4 . I f n o t O K , r e p a i r t h e

open circuit to the horn(s) as required.

(4) The coil bat tery terminal (86) is connected to

the electromagnet in the relay. It is connected to bat-

tery voltage and should be hot at al l t imes. Check for

ba t t e r y v o l t a g e a t t h e c a v i t y f o r r e l a y t e r m i n a l 8 6 . I fOK, go to Step 5. If not OK, repair the open circuit to

the fuse in the junction block as required.

(5) The coil ground terminal (85) is connected to

t h e elect r om a gn et in t h e r ela y. I t is g rou nd ed

t h r ou gh t h e h or n s w it ch w h en t h e h or n s w it ch i s

depressed. Check for continuity to ground at the cav-

ity for relay terminal 85. There should be continuity

w i t h t h e h or n s w i t ch d ep re ss ed , a n d n o con t i nu it y

w i t h t h e h o r n s w i t ch r el ea s e d. I f n ot O K , s ee t h e

d i a g n o s i s f o r t h e H o r n Sw i t c h i n t h i s g r o u p .

HORN SWITCH

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o8W-41 - H orns/Ciga r Light er in G roup 8W - Wiring

Di a g r a m s .

WARNING: ON VEHICLES EQUIPPED WITH AIR-

BAGS, REFER TO GROUP 8M - PASSIVERESTRAINT SYSTEMS BEFORE ATTEMPTING ANYSTEERING WHEEL, STEERING COLUMN, ORINSTRUMENT PANEL COMPONENT DIAGNOSIS OR

SERVICE. FAILURE TO TAKE THE PROPER PRE-CAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONALINJURY.

(1) D is con n ect a n d i sol a t e t h e b a t t e r y n eg a t i ve

cable. Remove the steering column opening cover and

knee blocker. C heck for continuity between t he meta l

s t e er i n g col u m n ja c k et a n d a g ood g r ou n d . Th e r e

s h o u l d be c o n t i n u i t y . I f O K, g o t o St e p 2 . I f n o t O K,

r e fe r t o Gr o u p 1 9 - S t e er i n g a n d ch e ck f or p r op er

instal lation of the steering column mounting nuts.

(2) R em ov e t h e d r iv er s id e a i r ba g m od u le a s

d e s c r i be d i n Gr o u p 8 M - P a s s i v e R e s t r a i n t Sy s t e m s .

Unplug the horn switch wire harness connector from

t h e a i r b a g m o d u l e . U n p l u g t h e h o r n r e l a y f r o m t h e

Horn Relay

RELAY TERMINALSRELAY CAVITIES

8 G - 2 H OR N SY STEM S XJ


3/4

ju n ct i on bl ock . C h e ck f or con t i n u i t y bet w e e n t h e

s t eer i ng col um n h a l f of t h e h or n s w i t ch f ee d w i r e

ha rness connector and a good ground. There should

b e n o con t in u it y. I f O K, g o t o S t ep 3. I f n ot O K ,

repair the short circuit as required.

(3) Check for continuity between the steering col-

u m n h a l f o f t h e h o r n s w i t c h f e e d w i r e h a r n e s s c o n -n e ct o r a n d t h e h or n r e la y con t r o l c ir cu i t ca v i t y f or

the horn relay in the junction block. There should be

c o n t i n u i t y . I f O K, g o t o St e p 4 . I f n o t O K, r e p a i r t h e

open circuit as required.

(4) C h e ck f or con t i n u it y bet w e e n t h e h or n s w i t ch

f ee d w i r e a n d t h e h o r n s w i t ch g r ou n d w i r e on t h e

airbag module. There should be no continuity. If OK,

g o t o S t ep 5. I f n ot O K , r e pl a ce t h e f a ul t y h or n

switch.

(5) Depress the center of the airbag module cover

a n d ch eck f or con t i nu it y b et w e en t h e h or n s w i t ch

f ee d w i r e a n d t h e h o r n s w i t ch g r ou n d w i r e on t h e

airbag module. There should now be continuity. If notO K, r e p l a c e t h e f a u l t y h o r n s w i t c h .

HORN

F or ci r cu it d es cr i pt i on s a n d d ia g r a m s , r ef er t o

8W-41 - H orns/Ciga r Light er in G roup 8W - Wiring

Di a g r a m s .

(1) M ea s ur e t h e r es is t a n ce b et w een t h e h or n

m ou n t i n g br a c ke t a n d a g ood g r ou n d . Th e r e s h ou l d

be z e r o o h m s r e s i s t a n c e . I f O K, g o t o St e p 2 . I f n o t

OK, repair the horn ground connection as required.

(2) U n p lu g t h e h or n w i re h a r n es s con n ect or.

D e pr es s t h e h or n s w i t ch . Th er e s h ou ld b e b a t t e r y

v ol t a g e a t t h e h or n w i r e h a r n es s con n ect or. I f O K ,r e pl a ce t h e f a u l t y h or n . I f n o t O K, r e pa i r t h e o pe n

ci r cu i t t o t h e h or n r e la y a s r e q u ir e d.

REMOVAL AND INSTALLATION

HORN RELAY

WARNING: ON VEHICLES EQUIPPED WITH AIR-BAGS, REFER TO GROUP 8M - PASSIVE

RESTRAINT SYSTEMS BEFORE ATTEMPTING ANYSTEERING WHEEL, STEERING COLUMN, OR

INSTRUMENT PANEL COMPONENT DIAGNOSIS ORSERVICE. FAILURE TO TAKE THE PROPER PRE-

CAUTIONS COULD RESULT IN ACCIDENTAL AIR-BAG DEPLOYMENT AND POSSIBLE PERSONALINJURY.

(1) D is con n ect a n d i sol a t e t h e b a t t e r y n eg a t i ve

cable.

(2) Remove the fuse access panel by unsnapping i t

f r om t h e r i g h t cow l s i de t r i m p a n e l .

(3) Remove the stamped nut that secures the right

cowl side trim to the junction block stud (Fig. 1).

(4) Remove the screw located above the fuse access

o p e n i n g t h a t s e c u r e s t h e r i g h t c o w l s i d e t r i m t o t h e

right cowl side inner panel .

(5) R e mov e t h e s cr e w t h a t s ecu r es t h e r i g h t d oor

s il l t r i m a n d t h e r i gh t cow l s id e t r i m t o t h e r ig ht

door opening sill .

(6) Remove the right cowl side trim panel from the

vehicle.

(7) Unplug the horn relay from the junction block.

(8) I n s t a l l t h e h or n r e l a y by a l i gn i n g t h e r e l a y t e r-m in a l s w i t h t h e ca v i t ie s i n t h e ju n ct i on b lock a n d

pushing the relay firmly into place.

(9) Connect the battery negative cable.

(10) Test the relay opera tion.

(11) I n s t a l l t h e r i g h t c ow l s i d e t r i m a n d t h e f u s e

access panel.

Fig. 1 Right Cowl Side Trim Remove/Install

RIGHT FRONT DOOR SILLCOWL SIDE TRIM PANELSCREWSILL TRIMFUSE ACCESS PANELFWD PUSH-NUT

XJ H OR N SY STEM S 8 G - 3

DIAGNOSIS AND TESTING (Continued)


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HORN SWITCH

WARNING: ON VEHICLES EQUIPPED WITH ADRIVER SIDE AIRBAG, THE HORN SWITCH IS INTE-GRAL TO THE AIRBAG MODULE TRIM COVER.

SERVICE OF THIS COMPONENT SHOULD BE PER-

FORMED ONLY BY CHRYSLER-TRAINED ANDAUTHORIZED DEALER SERVICE TECHNICIANS.FAILURE TO TAKE THE PROPER PRECAUTIONS

OR TO FOLLOW THE PROPER PROCEDURESCOULD RESULT IN ACCIDENTAL, INCOMPLETE, ORIMPROPER AIRBAG DEPLOYMENT AND POSSIBLEPERSONAL INJURY. REFER TO GROUP 8M - PAS-

SIVE RESTRAINT SYSTEMS FOR THE SERVICEPROCEDURES.

HORN

(1) D is con n ect a n d i sol a t e t h e b a t t e ry n eg a t i ve

cable.(2) Raise and support the vehicle.

(3) Remove the front underbody splash shield.

NOTE: Do not remove the horn from its mountingbracket.

(4) Remove the horn mounting bra cket screw a nd

lower the horn and mounting bracket unit far enough

to access the wire harness connector (Fig. 2).

(5) U n p l u g t h e w i r e h a r n e s s con n e ct o r f r om t h e

horn.

(6) R e m ov e t h e h or n a n d m ou n t i n g br a c ke t f r om

the vehicle.(7) R ev er s e t h e r em ov a l p roce du r es t o i n st a l l .

Ti g h t en t h e h or n m ou n t i n g br a c ke t s cr e w t o 28.5

Nm (21 ft. lbs.).

Fig. 2 Horns Remove/Install

MOUNTING BOLTHORN

8 G - 4 H OR N SY STEM S XJ

REMOVAL AND INSTALLATION (Continued)

exj_8g99 jeep xj service manual

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