1999 DODGE RAM jump cable

knob pointer) is flush with base of A/C-heater control panel.
5) Rotate temperature control knob to its full clockwise
stop. Release knob. Knob pointer should be aimed at end of Red stripe.
If knob is pointed at end of Red stripe, go to next step. If knob is
not pointed at end of Red stripe, go back to step 2) and repeat
adjustment procedure.
6) Rotate temperature control knob to its full
counterclockwise stop. Release knob. If knob springs back, self-
adjuster clip securing temperature control cable to blend-air door
lever is improperly installed. See TEMPERATURE CONTROL CABLE R & I. If
knob does not spring back, temperature control cable adjustment is
complete.
TESTING
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
A/C-HEATER CONTROL PANEL TEST
1) Connect a vacuum gauge in line with Black A/C-heater
vacuum supply hose, located at tee near power brake booster (Dakota)
or in engine compartment (Durango and Ram Pickup). Position gauge so
it can be viewed from passenger compartment.
2) Start engine. While observing gauge, rotate mode control
knob to each mode position (one position at a time). Pause after each
selection. Test gauge should drop, then return to 8 in. Hg shortly
after each selection is made. If gauge reading is as specified, go to
next step. If gauge reading is not as specified, check for vacuum leak
in vacuum lines or A/C-heater control panel.
3) Move temperature control knob quickly to full hot and full
cold positions. A distinct sound of blend-air door hitting its stops
should be heard. No spring-back of knob should exist.
4) If temperature control knob operates as specified,
temperature control system is okay. On Dakota and Durango, if
temperature control knob does not operate as specified, check
condition, routing, installation, and adjustment of temperature
control cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT . Also check
blend air door for proper installation, obstructions, or faulty seals.
A/C SYSTEM PERFORMANCE
1) Park vehicle out of direct sunlight. Ensure ambient
temperature is at least 70F (21C). Connect tachometer and manifold
gauge set to vehicle. Turn A/C on. Turn mode control to panel and
recirculated air positions, temperature control lever to maximum
cooling, and blower to high.
2) Start engine and allow it to run at 1000 RPM, with A/C
compressor clutch engaged. Engine should be at operating temperature
with doors, windows, and hood closed. Insert thermometer into left
center air outlet.
3) Run engine and operate system for 5 minutes. The A/C
compressor clutch may cycle, depending on temperature. If A/C
compressor clutch cycles, stop engine and disconnect negative battery
cable. Remove clutch cycling pressure switch connector. Place a jumper
wire across terminals of clutch cycling pressure switch harness
connector.
4) Connect negative battery cable. Turn A/C on. Start and

A/C SYSTEM PERFORMANCE PRESSURE SPECIFICATIONS (RAM PICKUP)








\









\









\









\









\









\









\







Ambient Temp. High Side Low SideF (C) psi (kg/cm) psi (kg/cm)
70 (21) .............. 135-145 (9.5-10.2) ........ 35-40 (2.5-2\
.8)
80 (27) .............. 175-215 (12.3-15.1) ....... 40-50 (2.8-3\
.5)
90 (32) .............. 215-270 (15.1-19.0) ....... 50-60 (3.5-4\
.2)
100 (38) ............. 270-330 (19.0-23.2) ....... 60-70 (4.2-4\
.9)
110 (43) ............. 340-370 (23.9-26.0) ....... 70-80 (4.9-5\
.6)
120 (49) ............. 400-430 (28.1-30.2) ....... 85-90 (6.0-6\
.3)









\









\









\









\









\









\









\







BLOWER MOTOR RELAY, HIGH SPEED BLOWER MOTOR RELAY &
COMPRESSOR CLUTCH RELAY
NOTE: Relays appear different, but testing procedures for blower
motor, high speed blower motor, and compressor clutch relays
are identical.
1) Front blower motor relay and compressor clutch relay are
located in Power Distribution Center (PDC). On Durango, high speed
blower motor relay is located in fuse/relay block under left side of
instrument panel.
2) Disconnect negative battery cable. Remove blower motor or
compressor clutch relay. Using an ohmmeter, check for continuity
between terminals No. 87A and 30 of relay. See Fig. 1 or 2. If
continuity does not exist, replace relay. If continuity exists, go to
next step.
3) Using an ohmmeter, check for continuity between terminals
No. 30 and 87 of relay. If continuity exists, replace relay. If
continuity does not exist, go to next step.
4) Measure resistance between terminals No. 85 and 86 of
relay. Reading should be 70-80 ohms. If reading is not as specified,
replace relay. If reading is as specified, go to next step.
5) Using jumper wires, connect battery voltage to terminal
No. 86 and ground terminal No. 85. See Fig. 1 or 2. Check that
continuity exists between terminals No. 30 and 87. Check that
continuity does not exist between terminals No. 87A and 30. If
continuity is not as specified, replace relay. If continuity is as
specified, relay is okay.
Fig. 1: Identifying Blower Motor Relay Terminals (Typical)
Courtesy of Chrysler Corp.

control panel and blower motor.
Fig. 3: Identifying Blower Motor Switch Connector Terminals (Typical)\
Courtesy of Chrysler Corp.
Rear (Durango)
1) Disconnect negative battery cable. Remove rear blower
motor switch located in headliner. See BLOWER MOTOR SWITCH (REAR)
under REMOVAL & INSTALLATION. Disconnect rear blower motor switch
connector. Using an ohmmeter, check continuity between rear blower
motor switch connector Black wire and ground. If continuity exists, go
to next step. If continuity does not exist, repair open in Black wire
between rear blower motor switch connector and ground connector
located at left rear of vehicle body.
2) Place blower motor switch knob to any position except OFF.
Using an ohmmeter, check for continuity between rear blower motor
switch connector Black wire and Black/Light Blue wire, and
Black/Orange wire and Dark Green wire while rotating blower motor
switch.
3) If continuity does not exist at any terminal, replace
faulty blower motor switch. If continuity exists as specified, check
for open in circuits between blower motor switch and blower motor
resistor. Also check for an open in circuit between blower motor
switch connector and blower motor relay.
CLUTCH CYCLING PRESSURE SWITCH
Dakota & Ram Pickup
1) Locate clutch cycling pressure switch on side or top of
A/C accumulator. Ensure clutch cycling pressure switch is properly
installed on A/C accumulator fitting. Ensure system pressure is
correct. See A/C SYSTEM PERFORMANCE test.
2) Start and run engine with A/C on. If clutch cycles, turn
engine off and disconnect negative battery cable. Disconnect clutch
cycling pressure switch connector. Place a jumper wire across
terminals of clutch cycling pressure switch harness connector. Connect
negative battery cable. Connect manifold gauge set. Set A/C-heater

1) Locate low pressure cut-out switch located on suction
line, near firewall. Ensure system pressure is correct. See
A/C SYSTEM PERFORMANCE test. Disconnect negative battery cable.
Disconnect low pressure cut-out switch connector.
2) Place a jumper wire across terminals of low pressure cut-
out switch harness connector. Connect negative battery cable. Connect
manifold gauge set. Set A/C-heater controls to A/C. Start and operate
engine at idle speed.
3) Using an ohmmeter, check for continuity between switch
terminals. Continuity should exist when suction pressure reading is
between 13-27 psi (.9-1.9 kg/cm
). Continuity should not exist when
suction pressure reading is 10 psi (.7 kg/cm) or lower. If switch is
okay, repair open or short in Brown wire between low pressure cut-out
switch and PCM. If switch is not okay, replace faulty low pressure
cut-out switch.
REMOVAL & INSTALLATION
* PLEASE READ THIS FIRST *
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
A/C-HEATER ASSEMBLY
Removal (Dakota & Durango - Front)
1) Disconnect negative battery cable. Drain cooling system.
Discharge A/C system, using approved refrigerant recovery/recycling
equipment. Disconnect refrigerant lines from evaporator and plug or
cover all openings in A/C system. Remove instrument panel. See
INSTRUMENT PANEL .
2) In engine compartment, disconnect heater hoses. Remove 4
A/C-heater assembly nuts from engine compartment firewall. Inside
vehicle, remove A/C-heater assembly support brace screw, and swing
support brace out of way. Move passenger seat rearward.
3) Carefully pull A/C-heater assembly rearward until studs
and heater core tubes clear firewall. Lower A/C-heater assembly and
rotate assembly until studs are facing downward. Remove A/C-heater
assembly from vehicle. See Fig. 4.
4) Place A/C-heater assembly on work bench with assembly
housing cover facing down. Remove 2 screws securing A/C-heater
assembly housing cover to blower motor housing cover. Unplug vacuum
harness connector from panel/defrost door actuator.
5) Remove floor duct from A/C-heater assembly housing. Remove
2 screws securing A/C-heater assembly housing cover to lower housing
near floor outlet. Turn assembly over. Disengage vacuum harness
retainer and vacuum harness. Remove 13 screws securing housing cover.
6) Remove blend-air door lever. Gently pry panel-defrost door
lever off. Pull up on A/C-heater assembly housing cover far enough to
separate cover sealant and remove cover.
Installation
Ensure blower motor housing cover sealant is in place and in
good condition. To complete installation, reverse removal procedure.

inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Ensure ignition switch is in the RUN position. Disconnect
Powertrain Control Module (PCM) connectors. If DRB does not display
BUS SHORT TO BATTERY, to step 8). If DRB displays BUS SHORT TO
BATTERY, go to next step.
2) Disconnect instrument cluster connectors. If DRB does not
display BUS SHORT TO BATTERY, replace instrument cluster. If DRB
displays BUS SHORT TO BATTERY, go to next step.
3) Turn ignition off and wait 2 minutes before proceeding.
Disconnect air bag control module connector. Turn ignition on (engine
off). If DRB does not display SHORT TO BATTERY, replace ACM. If DRB
displays SHORT TO BATTERY, go to next step.
4) Disconnect Central Timer Module (CTM) 18-pin connector. I\
f
DRB does not display BUS SHORT TO BATTERY, replace CTM. If DRB
displays BUS SHORT TO BATTERY, go to next step.
5) Disconnect anti-lock brake controller. If DRB does not
display BUS SHORT TO BATTERY, replace anti-lock brake controller. If
DRB displays BUS SHORT TO BATTERY, go to next step.
6) Disconnect DRB from Data Link Connector (DLC). Using a
voltmeter, check voltage between ground and DLC connector terminal No.
3 (Violet/Brown wire). If voltage is more than 0.2 volt, repair short
in Violet/Brown wire. If voltage is less than 0.2 volt, go to next
step.
7) Using a voltmeter, check voltage between ground and DLC
connector terminal No. 11 (White/Black wire). If voltage is more than
0.2 volt, repair short in White/Black wire. If voltage is less than 0.
2 volt, replace DRB or DRB cable as necessary.
8) Turn ignition off. Using an ohmmeter, check resistance
between ground and PCM Black connector terminal A31 (Black/Tan wire).
If resistance is more than 10 ohms, repair open in Black/Tan wire). If
resistance is less than 10 ohms, go to next step.
9) Using an ohmmeter, check resistance between ground and PCM
Black connector terminal A32 (Black/Tan wire). If resistance is more
than 10 ohms, repair open in Black/Tan wire). If resistance is less
than 10 ohms, replace Powertrain Control Module (PCM).
NO RESPONSE FROM INSTRUMENT CLUSTER
NOTE: Perform COMPONENT VERIFICATION TEST under DIAGNOSTIC TESTS
after all repairs. Each time a connector is disconnected,
inspect it to ensure it is in good condition. Always focus on
circuit being tested. Dirt, water and corrosion, are most
common problems in connectors. Due to manufacturer changes in
wire colors, use terminal identification whenever possible.
1) Remove Instrument cluster. Using DRB, turn on INTERNAL BUS
BIAS under SYSTEM MONITORS CCD BUS VOLTAGE. Connect a jumper wire from
Black instrument cluster 10-pin connector "A" terminal No. 9
(White/Black wire) to ground. Observe CCD BUS voltage on DRB. If
voltage did not drop to about zero volt, repair open in White/Black
wire. If voltage drops to about zero volt, go to next step.
2) Leave internal DRB CCD BUS BIAS turned on. Connect a
jumper wire from ground to Black instrument cluster 10-pin connector
"A" terminal No. 10 (Violet/Brown wire). Go to next step.
3) Observe CCD BUS voltage on DRB. If voltage did not drop to
about zero volt, repair open in Violet/Brown wire. If voltage drops to
about zero volt, replace instrument cluster.

operator's foot off accelerator pedal, S/C compensates for excessive
S/C cable slack. If lift foot sets are continually used, speed control
overshoot/undershoot condition will develop.
To "unlearn" overshoot/undershoot condition, operator must
press and release set button while maintaining desired speed with
accelerator pedal, then turn S/C switch to OFF position after waiting
10 seconds. This procedure must be repeated 10-15 times to completely
unlearn overshoot/undershoot condition.
COMPONENT TESTS
WARNING: Vehicle is equipped with an air bag. Air bag must be
deactivated before servicing speed control components on or
around steering column. See appropriate AIR BAG RESTRAINT
SYSTEMS article.
NOTE: For component locations, See COMPONENT LOCATIONS. For
connector terminal identification, see CONNECTOR
IDENTIFICATION. For wiring diagram, see WIRING DIAGRAMS.
BRAKE SWITCH
Disconnect brake switch 6-pin connector. Using an ohmmeter,
check for continuity at brake switch. See Fig. 1. If continuity is not
as specified in BRAKE SWITCH CONTINUITY table, check brake switch
adjustment. See BRAKE SWITCH under REMOVAL & INSTALLATION. If brake
switch adjustment is okay, replace defective brake switch.
BRAKE SWITCH CONTINUITY








\









\









\









\









\









\









\






 
Switch Plunger  Check Between  Continuity 


Position  Terminals  










\









\

\b







\









\









\


\b







\









\






Released  5 & 6  Yes 










\









\

\b







\









\









\


\b







\









\






Depressed  1 & 2  Yes 











\









\









\
\b








\









\





 3 & 4  Yes 











\









\









\









\









\









\









\





\f

SPEED CONTROL SERVO
1) Start engine. Disconnect Speed Control (S/C) servo 4-pin
connector. Turn S/C on. Using a voltmeter, check voltage at S/C servo
connector terminal No. 3 (Dark Blue/Red wire). Battery voltage should
exist when brake pedal is not depressed. If battery voltage exists, go
to next step. If battery voltage does not exist, check circuit between
brake switch and S/C servo. See WIRING DIAGRAMS.
2) Connect a jumper wire between S/C servo pin No. 3 and S/C
servo connector terminal No. 3. Check voltage at S/C servo pins No. 1,
2 and 4. If battery voltage does not exist, replace S/C servo. If
battery voltage exists, go to next step.
3) Turn ignition off. Check for continuity between S/C servo
connector terminal No. 4 and ground. If continuity exists, test is
complete. If continuity does not exist, repair open ground circuit as
necessary.
VACUUM SUPPLY
Gasoline Engines
1) Disconnect vacuum hose at speed control servo. Install
vacuum gauge to disconnected vacuum hose. Start engine and observe

TROUBLE SHOOTING
NOTE: To trouble shoot mechanical engine components, see
appropriate table in TROUBLE SHOOTING article in GENERAL
INFORMATION.
REMOVAL & INSTALLATION
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
NOTE: For installation reference, label all electrical connectors,
vacuum hoses and fuel lines before removal. Also place mating
marks on engine hood and other major assemblies before
removal.
FUEL PRESSURE RELEASE
CAUTION: Fuel system is under pressure. Pressure must be released
before servicing fuel system components.
Gasoline
1) Disconnect negative battery cable. Loosen fuel tank cap to
release tank pressure. Press on filler tube flap to relieve any
additional tank pressure.
NOTE: Fuel filler tube has spring-loaded flap located below fuel
fill cap to serve as secondary seal if fuel fill cap is not
tightened. It is part of EVAP monitor system when vehicle is
equipped with leak detection pump (LDP). Vehicle may be
equipped with flap installed into fuel filler tube even if
vehicle is NOT equipped with LDP and EVAP monitor system.
2) Remove fuel pump relay from Power Distribution Center
(PDC). For location of relay, refer to label on underside of PDC
cover. Start and run engine until it stalls. Attempt restarting engine
until it will no longer run.
3) Unplug connector from an injector. Attach one end of a
jumper wire (18 gauge or smaller) with alligator clips to either
injector terminal. Connect other end of jumper wire to positive side
of battery. Connect one end of a second jumper wire to remaining
injector terminal.
WARNING: Powering an injector for more than a few seconds will
permanently damage injector.
4) Touch other end of second jumper wire to negative terminal
of battery for no more than a few seconds. Place a rag below fuel
line. Disconnect quick-connect fitting at fuel rail. See FUEL LINE
DISCONNECT FITTINGS. Return fuel pump relay to PDC.
Compressed Natural Gas Fuel Tube Purging (5.2L)
1) Close control valve (clockwise) on all fuel cylinders.
Open manual shutoff valve (open when handle is parallel to fuel
tubes).
2) Start and operate engine until it runs out of fuel.
Attempt 3 more engine starts. If check valve or fuel fill receptacle

pointer is at one o'clock position. Push in on knob slightly and
continue rotating knob to its full clockwise stop. Place knob pointer
at a position about .32" (8 mm) beyond end of Red stripe. Release
knob. If knob is pointing at about .32" (8 mm) beyond end of Red
stripe, go to next step. If knob is not pointing at about .32" (8 mm)
beyond end of Red stripe, go back to step 2) and repeat adjustment
procedure.
4) Rotate temperature control knob counterclockwise so that
knob pointer is at 12 o'clock position. Push temperature control knob
straight into heater control panel until perimeter of knob (not knob
pointer) is flush with base of heater control panel.
5) Rotate temperature control knob to its full clockwise
stop. Release knob. Knob pointer should be aimed at end of Red stripe.
If knob is pointed at end of Red stripe, go to next step. If knob is
not pointed at end of Red stripe, go back to step 2) and repeat
adjustment procedure.
6) Rotate temperature control knob to its full
counterclockwise stop. Release knob. If knob springs back, self-
adjuster clip securing temperature control cable to blend-air door
lever is improperly installed. See TEMPERATURE CONTROL CABLE R & I
under REMOVAL & INSTALLATION. If knob does not springs back,
temperature control cable adjustment is complete.
TROUBLE SHOOTING
HEATER PERFORMANCE
Check cooling system. Check serpentine drive belt tension.
Check radiator and radiator fan operation. Ensure that accessory
vacuum supply line is connected at power brake booster (Dakota) or
engine vacuum source (except Dakota).
TESTING
WARNING: To avoid injury from accidental air bag deployment, read and
carefully follow all SERVICE PRECAUTIONS and DISABLING &
ACTIVATING AIR BAG SYSTEM procedures in AIR BAG SYSTEM SAFETY
article.
BLOWER MOTOR RELAYS
1) Blower motor relay is located in Power Distribution Center
(PDC). On Ram Van/Wagon, high speed blower motor relay is located in
engine compartment (on side of heater assembly). On all models,
disconnect negative battery cable. Remove blower motor relay. Using an
ohmmeter, check for continuity between terminals No. 87A and 30 of
relay. See Fig. 1. If continuity does not exist, replace relay. If
continuity exists, go to next step.
2) Using an ohmmeter, check for continuity between terminals
No. 30 and 87 of relay. If continuity exists, replace relay. If
continuity does not exist, go to next step.
3) Measure resistance between terminals No. 85 and 86 of
relay. Reading should be 70-80 ohms. If reading is not as specified,
replace relay. If reading is as specified, go to next step.
4) Using jumper wires, connect battery voltage to terminal
No. 86 and ground terminal No. 85. See Fig. 1. Check that continuity
exists between terminals No. 30 and 87. Check that continuity does not
exist between terminals No. 87A and 30. If continuity is not as
specified, replace blower motor relay. If continuity is as specified,
relay is okay.