t h e h ea t er cor e, h ea t r em oved fr om t h e en gin e is
t r a n sfer r ed t o t h e h ea t er cor e fin s a n d t u bes.
Air dir ect ed t h r ou gh t h e h ea t er cor e picks u p t h e
h ea t fr om t h e h ea t er cor e fin s. Th e blen d a ir door
a llows con t r ol of t h e h ea t er ou t pu t a ir t em per a t u r e
by con t r ollin g h ow m u ch of t h e a ir flowin g t h r ou gh
t h e h ea t er-A/C h ou sin g is dir ect ed t h r ou gh t h e
h ea t er cor e. Th e blower m ot or speed con t r ols t h e vol-
u m e of a ir flowin g t h r ou gh t h e h ea t er-A/C h ou sin g.
Th e h ea t er cor e ca n n ot be r epa ir ed a n d, if fa u lt y or
da m a ged, it m u st be r epla ced. Refer t o Gr ou p 7 -
Coolin g Syst em for m or e in for m a t ion on t h e en gin e
coolin g syst em , t h e en gin e coola n t a n d t h e h ea t er
h oses.
HIGH PRESSURE CUT-OFF SWITCH
Th e h igh pr essu r e cu t -off swit ch is loca t ed on t h e
disch a r ge lin e bet ween t h e com pr essor a n d t h e con -
den ser in let . Th e swit ch is scr ewed on t o a fit t in g t h a t
con t a in s a Sch r a der-t ype va lve, wh ich a llows t h e
swit ch t o be ser viced wit h ou t disch a r gin g t h e r efr ig-
er a n t syst em . Th e disch a r ge lin e fit t in g is equ ipped
wit h a n O-r in g t o sea l t h e swit ch con n ect ion .
Th e h igh pr essu r e cu t -off swit ch is con n ect ed in
ser ies elect r ica lly wit h t h e low pr essu r e cyclin g
clu t ch swit ch bet ween gr ou n d a n d t h e P ower t r a in
Con t r ol Modu le (P CM). Th e swit ch con t a ct s open a n d
close ca u sin g t h e P CM t o t u r n t h e com pr essor clu t ch
on a n d off. Th is pr even t s com pr essor oper a t ion wh en
t h e disch a r ge lin e pr essu r e a ppr oa ch es h igh levels.
Th e h igh pr essu r e cu t -off swit ch con t a ct s a r e open
wh en t h e disch a r ge lin e pr essu r e r ises a bove 3100 t o
3375 kP a (450 t o 490 psi). Th e swit ch con t a ct s will
close wh en t h e disch a r ge lin e pr essu r e dr ops t o 1860
t o 2275 kP a (270 t o 330 psi).
Th e h igh pr essu r e cu t -off swit ch is a fa ct or y-ca li-
br a t ed u n it . Th e swit ch ca n n ot be a dju st ed or
r epa ir ed a n d, if fa u lt y or da m a ged, it m u st be
r epla ced.
HIGH PRESSURE RELIEF VALVE
A h igh pr essu r e r elief va lve is loca t ed on t h e com -
pr essor cylin der h ea d, wh ich is a t t h e r ea r of t h e
com pr essor. Th is m ech a n ica l va lve is design ed t o
ven t r efr iger a n t fr om t h e syst em t o pr ot ect a ga in st
da m a ge t o t h e com pr essor a n d ot h er syst em com po-
n en t s, ca u sed by con den ser a ir flow r est r ict ion or a n
over ch a r ge of r efr iger a n t .
Th e h igh pr essu r e r elief va lve ven t s t h e syst em
wh en a disch a r ge pr essu r e of 3445 t o 4135 kP a (500
t o 600 psi) or a bove is r ea ch ed. Th e va lve closes
wh en a m in im u m disch a r ge pr essu r e of 2756 kP a
(400 psi) is r ea ch ed.
Th e h igh pr essu r e r elief va lve ven t s on ly en ou gh
r efr iger a n t t o r edu ce t h e syst em pr essu r e, a n d t h en
r e-sea t s it self. Th e m a jor it y of t h e r efr iger a n t is con -
ser ved in t h e syst em . If t h e va lve ven t s r efr iger a n t , it
does n ot m ea n t h a t t h e va lve is fa u lt y.
Th e h igh pr essu r e r elief va lve is a fa ct or y-ca li-
br a t ed
u n it . Th e
va lve
ca n n ot
be
a dju st ed
or
r epa ir ed, a n d m u st n ot be r em oved or ot h er wise dis-
t u r bed. Th e va lve is on ly ser viced a s a pa r t of t h e
com pr essor a ssem bly.
LOW PRESSURE CYCLING CLUTCH SWITCH
Th e low pr essu r e cyclin g clu t ch swit ch is loca t ed
on t h e t op of t h e a ccu m u la t or. Th e swit ch is scr ewed
on t o a n a ccu m u la t or fit t in g t h a t con t a in s a Sch r a der-
t ype va lve, wh ich a llows t h e swit ch t o be ser viced
wit h ou t disch a r gin g t h e r efr iger a n t syst em . Th e
a ccu m u la t or fit t in g is equ ipped wit h a n O-r in g t o
sea l t h e swit ch con n ect ion .
Th e low pr essu r e cyclin g clu t ch swit ch is con n ect ed
in ser ies elect r ica lly wit h t h e h igh pr essu r e cu t -off
swit ch , bet ween gr ou n d a n d t h e P ower t r a in Con t r ol
Modu le (P CM). Th e swit ch con t a ct s open a n d close
ca u sin g t h e P CM t o t u r n t h e com pr essor clu t ch on
a n d off. Th is r egu la t es t h e r efr iger a n t syst em pr es-
su r e a n d con t r ols eva por a t or t em per a t u r e. Con t r ol-
lin g t h e eva por a t or t em per a t u r e pr even t s con den sa t e
wa t er on t h e eva por a t or fin s fr om fr eezin g a n d
obst r u ct in g a ir con dit ion in g syst em a ir flow.
Th e low pr essu r e cyclin g clu t ch swit ch con t a ct s a r e
open wh en t h e su ct ion pr essu r e is a ppr oxim a t ely 141
kP a (20.5 psi) or lower. Th e swit ch con t a ct s will close
wh en t h e su ct ion pr essu r e r ises t o a ppr oxim a t ely 234
t o 262 kP a (34 t o 38 psi) or a bove. Lower a m bien t
t em per a t u r es, below a ppr oxim a t ely -1° C (30° F ), will
a lso ca u se t h e swit ch con t a ct s t o open . Th is is du e t o
t h e pr essu r e/t em per a t u r e r ela t ion sh ip of t h e r efr iger-
a n t in t h e syst em .
Th e low pr essu r e cyclin g clu t ch swit ch is a fa ct or y-
ca libr a t ed u n it . It ca n n ot be a dju st ed or r epa ir ed
a n d, if fa u lt y or da m a ged, it m u st be r epla ced.
REFRIGERANT
Th e r efr iger a n t u sed in t h is a ir con dit ion in g sys-
t em is a H ydr oF lu or oCa r bon (H F C), t ype R-134a .
Un like R-12, wh ich is a Ch lor oF lu or oCa r bon (CF C),
R-134a r efr iger a n t does n ot con t a in ozon e-deplet in g
ch lor in e. R-134a r efr iger a n t is a n on -t oxic, n on -fla m -
m a ble, clea r, a n d color less liqu efied ga s.
E ven t h ou gh R-134a does n ot con t a in ch lor in e, it
m u st be r ecla im ed a n d r ecycled ju st like CF C-t ype
r efr iger a n t s. Th is is beca u se R-134a is a gr een h ou se
ga s a n d ca n con t r ibu t e t o globa l wa r m in g.
R-134a r efr iger a n t is n ot com pa t ible wit h R-12
r efr iger a n t in a n a ir con dit ion in g syst em . E ven a
sm a ll a m ou n t of R-12 a dded t o a n R-134a r efr iger a n t
syst em will ca u se com pr essor fa ilu r e, r efr iger a n t oil
slu dge or poor a ir con dit ion in g syst em per for m a n ce.
In a ddit ion , t h e P olyAlkylen e Glycol (PAG) syn t h et ic
24 - 8
HEATING AND AIR CONDITIONING
X J
DESCRI PT I ON AN D OPERAT I ON (Cont inue d)
Summary of Contents for Cherokee 1999
Page 1: ...HOFRPH WR WKH HHS KHURNHH OHFWURQLF 6HUYLFH 0DQXDO OLFN 2Q 7KH RJR 7R HJLQ...
Page 19: ...Fig 1 Wheel Alignment Measurements 2 2 SUSPENSION XJ GENERAL INFORMATION Continued...
Page 35: ......
Page 53: ...FRONT AXLES DIAGNOSIS 3 18 DIFFERENTIAL AND DRIVELINE XJ DIAGNOSIS AND TESTING Continued...
Page 54: ...DIAGNOSIS CONTINUED XJ DIFFERENTIAL AND DRIVELINE 3 19 DIAGNOSIS AND TESTING Continued...
Page 77: ...Fig 61 Gear Tooth Contact Patterns 3 42 DIFFERENTIAL AND DRIVELINE XJ ADJUSTMENTS Continued...
Page 86: ...DIAGNOSIS CHART XJ DIFFERENTIAL AND DRIVELINE 3 51 DIAGNOSIS AND TESTING Continued...
Page 87: ...DIAGNOSIS CHART CONTINUED 3 52 DIFFERENTIAL AND DRIVELINE XJ DIAGNOSIS AND TESTING Continued...
Page 112: ...Fig 79 Gear Tooth Contact Patterns XJ DIFFERENTIAL AND DRIVELINE 3 77 ADJUSTMENTS Continued...
Page 122: ...DIAGNOSIS CHART XJ DIFFERENTIAL AND DRIVELINE 3 87 DIAGNOSIS AND TESTING Continued...
Page 123: ...DIAGNOSIS CHART CONTINUED 3 88 DIFFERENTIAL AND DRIVELINE XJ DIAGNOSIS AND TESTING Continued...
Page 143: ...Fig 59 Gear Tooth Contact Patterns 3 108 DIFFERENTIAL AND DRIVELINE XJ ADJUSTMENTS Continued...
Page 185: ......
Page 189: ...Clutch Components 6 4 CLUTCH XJ DIAGNOSIS AND TESTING Continued...
Page 243: ......
Page 251: ...COOLING SYSTEM DIAGNOSIS DIESEL ENGINE 7 8 COOLING SYSTEM XJ DIAGNOSIS AND TESTING Continued...
Page 252: ...XJ COOLING SYSTEM 7 9 DIAGNOSIS AND TESTING Continued...
Page 253: ...7 10 COOLING SYSTEM XJ DIAGNOSIS AND TESTING Continued...
Page 254: ...XJ COOLING SYSTEM 7 11 DIAGNOSIS AND TESTING Continued...
Page 255: ...7 12 COOLING SYSTEM XJ DIAGNOSIS AND TESTING Continued...
Page 260: ...SERPENTINE DRIVE BELT DIAGNOSIS XJ COOLING SYSTEM 7 17 DIAGNOSIS AND TESTING Continued...
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Page 979: ...Fig 26 ABS G Sensor 8W 90 34 8W 90 CONNECTOR LOCA TIONS XJ DESCRIPTION AND OPERATION Continued...
Page 980: ...Fig 27 Rear Lamps XJ 8W 90 CONNECTOR LOCA TIONS 8W 90 35 DESCRIPTION AND OPERATION Continued...
Page 983: ...Fig 30 Liftgate 8W 90 38 8W 90 CONNECTOR LOCA TIONS XJ DESCRIPTION AND OPERATION Continued...
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Page 1034: ...Oil Lubrication System 2 5L Engine XJ 2 5L ENGINE 9 17 DESCRIPTION AND OPERATION Continued...
Page 1075: ...Oil Lubrication System 4 0L Engine 9 58 4 0L ENGINE XJ DESCRIPTION AND OPERATION Continued...
Page 1116: ...XJ ENGINE 9 3 DIAGNOSIS AND TESTING Continued...
Page 1117: ...9 4 ENGINE XJ DIAGNOSIS AND TESTING Continued...
Page 1118: ...XJ ENGINE 9 5 DIAGNOSIS AND TESTING Continued...
Page 1119: ...9 6 ENGINE XJ DIAGNOSIS AND TESTING Continued...
Page 1120: ...XJ ENGINE 9 7 DIAGNOSIS AND TESTING Continued...
Page 1121: ...9 8 ENGINE XJ DIAGNOSIS AND TESTING Continued...
Page 1122: ...XJ ENGINE 9 9 DIAGNOSIS AND TESTING Continued...
Page 1123: ...9 10 ENGINE XJ DIAGNOSIS AND TESTING Continued...
Page 1124: ...XJ ENGINE 9 11 DIAGNOSIS AND TESTING Continued...
Page 1159: ...SPECIFICATIONS ENGINE SPECIFICA TIONS 9 46 ENGINE XJ...
Page 1160: ...XJ ENGINE 9 47 SPECIFICATIONS Continued...
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Page 1188: ...Fig 6 Frame Dimensions XJ FRAME AND BUMPERS 13 7 SPECIFICATIONS Continued...
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Page 1293: ...Fig 1 Recirculating Ball Type Gear 19 12 STEERING XJ DESCRIPTION AND OPERATION Continued...
Page 1307: ...SPECIAL TOOLS STEERING LINKAGE Puller C 3894 A Remover Pitman C 4150A 19 26 STEERING XJ...
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Page 1504: ...DIAGNOSIS TABLE XJ TRANSMISSION AND TRANSFER CASE 21 181 DIAGNOSIS AND TESTING Continued...
Page 1600: ...A W 4 TORQUE SPECIFICA TIONS XJ TRANSMISSION AND TRANSFER CASE 21 277 SPECIFICATIONS Continued...
Page 1702: ...Fig 3 Hood Components XJ BODY 23 21 REMOVAL AND INSTALLATION Continued...
Page 1740: ...WELD LOCA TIONS UPPER COWL XJ BODY 23 59 SPECIFICATIONS Continued...
Page 1741: ...UPPER COWL 23 60 BODY XJ SPECIFICATIONS Continued...
Page 1742: ...COWL XJ BODY 23 61 SPECIFICATIONS Continued...
Page 1743: ...A PILLAR 23 62 BODY XJ SPECIFICATIONS Continued...
Page 1744: ...A PILLAR XJ BODY 23 63 SPECIFICATIONS Continued...
Page 1745: ...A PILLAR 23 64 BODY XJ SPECIFICATIONS Continued...
Page 1746: ...A PILLAR XJ BODY 23 65 SPECIFICATIONS Continued...
Page 1747: ...B PILLAR 23 66 BODY XJ SPECIFICATIONS Continued...
Page 1748: ...D PILLAR XJ BODY 23 67 SPECIFICATIONS Continued...
Page 1749: ...FUEL FILLER OPENING 23 68 BODY XJ SPECIFICATIONS Continued...
Page 1750: ...CARGO AREA FLOOR PAN XJ BODY 23 69 SPECIFICATIONS Continued...
Page 1751: ...ROOF AND D PILLAR 23 70 BODY XJ SPECIFICATIONS Continued...
Page 1752: ...LIFTGA TE OPENING XJ BODY 23 71 SPECIFICATIONS Continued...
Page 1753: ...ROOF 23 72 BODY XJ SPECIFICATIONS Continued...
Page 1754: ...ROOF XJ BODY 23 73 SPECIFICATIONS Continued...
Page 1755: ...FRAME RAIL 23 74 BODY XJ SPECIFICATIONS Continued...
Page 1756: ...FRAME RAIL XJ BODY 23 75 SPECIFICATIONS Continued...
Page 1757: ...FRAME RAIL 23 76 BODY XJ SPECIFICATIONS Continued...
Page 1758: ...FRAME RAIL XJ BODY 23 77 SPECIFICATIONS Continued...
Page 1759: ...REINFORCEMENT 23 78 BODY XJ SPECIFICATIONS Continued...
Page 1760: ...FRONT INNER FENDER XJ BODY 23 79 SPECIFICATIONS Continued...
Page 1761: ...FRONT INNER FENDER AND RADIA TOR CLOSURE PANEL 23 80 BODY XJ SPECIFICATIONS Continued...
Page 1762: ...REINFORCEMENT FRONT FENDER XJ BODY 23 81 SPECIFICATIONS Continued...
Page 1763: ...BODY SIDE 23 82 BODY XJ SPECIFICATIONS Continued...
Page 1764: ...REAR WHEELHOUSE XJ BODY 23 83 SPECIFICATIONS Continued...
Page 1765: ...REAR INNER WHEELHOUSE 23 84 BODY XJ SPECIFICATIONS Continued...
Page 1766: ...BODY SIDE XJ BODY 23 85 SPECIFICATIONS Continued...
Page 1767: ...BODY SIDE 23 86 BODY XJ SPECIFICATIONS Continued...
Page 1768: ...BODY SIDE XJ BODY 23 87 SPECIFICATIONS Continued...
Page 1769: ...BODY SIDE 23 88 BODY XJ SPECIFICATIONS Continued...
Page 1770: ...BODY SIDE XJ BODY 23 89 SPECIFICATIONS Continued...
Page 1771: ...BODY SIDE 23 90 BODY XJ SPECIFICATIONS Continued...
Page 1772: ...UNDERBODY XJ BODY 23 91 SPECIFICATIONS Continued...
Page 1773: ...UNDERBODY 23 92 BODY XJ SPECIFICATIONS Continued...
Page 1774: ...UNDERBODY XJ BODY 23 93 SPECIFICATIONS Continued...
Page 1775: ...UNDERBODY 23 94 BODY XJ SPECIFICATIONS Continued...
Page 1776: ...UNDERBODY XJ BODY 23 95 SPECIFICATIONS Continued...
Page 1777: ...UNDERBODY 23 96 BODY XJ SPECIFICATIONS Continued...
Page 1778: ...UNDERBODY XJ BODY 23 97 SPECIFICATIONS Continued...
Page 1779: ...UNDERBODY 23 98 BODY XJ SPECIFICATIONS Continued...
Page 1780: ...UNDERBODY XJ BODY 23 99 SPECIFICATIONS Continued...
Page 1781: ...UNDERBODY 23 100 BODY XJ SPECIFICATIONS Continued...
Page 1782: ...UNDERBODY XJ BODY 23 101 SPECIFICATIONS Continued...
Page 1783: ...BODY SEALING LOCA TIONS APPLICA TION METHODS 23 102 BODY XJ SPECIFICATIONS Continued...
Page 1784: ...COWL AND DASH PANEL XJ BODY 23 103 SPECIFICATIONS Continued...
Page 1785: ...DASH PANEL AND FLOOR PAN 23 104 BODY XJ SPECIFICATIONS Continued...
Page 1786: ...FLOOR PAN XJ BODY 23 105 SPECIFICATIONS Continued...
Page 1787: ...REAR INNER WHEELHOUSE 23 106 BODY XJ SPECIFICATIONS Continued...
Page 1788: ...FRONT INNER WHEELHOUSE XJ BODY 23 107 SPECIFICATIONS Continued...
Page 1789: ...BODY SIDE 23 108 BODY XJ SPECIFICATIONS Continued...
Page 1790: ...BODY SIDE XJ BODY 23 109 SPECIFICATIONS Continued...
Page 1791: ...BODY SIDE 23 110 BODY XJ SPECIFICATIONS Continued...
Page 1792: ...ROOF PANEL XJ BODY 23 111 SPECIFICATIONS Continued...
Page 1793: ...FUEL FILLER HOUSING 23 112 BODY XJ SPECIFICATIONS Continued...
Page 1794: ...LIFTGA TE OPENING XJ BODY 23 113 SPECIFICATIONS Continued...
Page 1795: ...STRUCTURAL ADHESIVE LOCA TIONS LEFT QUARTER PANEL 23 114 BODY XJ SPECIFICATIONS Continued...
Page 1796: ...REAR WHEELHOUSE XJ BODY 23 115 SPECIFICATIONS Continued...
Page 1797: ...ROOF BOWS 23 116 BODY XJ SPECIFICATIONS Continued...
Page 1798: ...BODY GAP AND FLUSH MEASUREMENTS XJ BODY 23 117 SPECIFICATIONS Continued...
Page 1805: ...ENGINE COMPARTMENT 23 124 BODY XJ SPECIFICATIONS Continued...
Page 1807: ...SPECIAL TOOLS BODY Remover Moldings C 4829 23 126 BODY XJ...
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Page 1940: ...FASTENER IDENTIFICATION XJ INTRODUCTION 5 GENERAL INFORMATION Continued...
Page 1941: ...FASTENER STRENGTH 6 INTRODUCTION XJ GENERAL INFORMATION Continued...
Page 1943: ...METRIC CONVERSION 8 INTRODUCTION XJ GENERAL INFORMATION Continued...
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