1999 DODGE RAM lock

REFILLING
To prevent air from being trapped in engine block, engine
should be running when refilling cooling system. After system is full,
continue running engine until thermostat is open, then recheck fill
level. Do not overfill system.
TESTING
THERMOSTAT
1) Visually inspect thermostat for corrosion and proper
sealing of valve and seat. If okay, suspend thermostat and thermometer
in a 50/50 mixture of coolant and water. See Fig. 1. Do not allow
thermostat or thermometer to touch bottom of container. Heat water
until thermostat just begins to open.
2) Read temperature on thermometer. This is the initial
opening temperature and should be within specification. Continue
heating water until thermostat is fully open and note temperature.
This is the fully opened temperature. If either reading is not to
specification, replace thermostat.
Fig. 1: Testing Thermostat in Anti-Freeze/Water Solution
PRESSURE TESTING
A pressure tester is used to check both radiator cap and

complete cooling system. Test components as follows, following tool
manufacturer's instructions.
Radiator Cap
Visually inspect radiator cap, then dip cap into water and
connect to tester. Pump tester to bring pressure to upper limit of cap
specification. If cap fails to hold pressure, replace cap.
Fig. 2: Testing Radiator Pressure Cap
Cooling System
1) With engine off, wipe radiator filler neck seat clean.
Fill radiator to correct level. Attach tester to radiator and pump
until pressure is at upper level of radiator rating.
2) If pressure drops, inspect for external leaks. If no leaks
are apparent, detach tester and run engine until normal operating
temperature is reached. Reattach tester and observe. If pressure
builds up immediately, a possible leak exists from a faulty head
gasket or crack in head or block.
NOTE: Pressure may build up quickly. Release any excess pressure
or cooling system damage may result.
3) If there is no immediate pressure build up, pump tester to
within system pressure range (on radiator cap). Vibration of gauge
pointer indicates compression or combustion leak into cooling system.
Isolate leak by shorting each spark plug wire to cylinder block. Gauge
pointer should stop or decrease vibration when leaking cylinder is
shorted.

HEA TE R S YSTE M

1999 D odge P ic ku p R 1500
1999 HEATER SYSTEMS
RWD Trucks & Vans
CHRYSLER
Dakota, Durango, Ram Pickup, Ram Van/Wagon
DESCRIPTION
All models use a blend-air system. Outside air enters heater
through cowl opening and passes through a plenum chamber to heater
core. Blend air door in heater housing controls temperature by either
directing air through or around heater core. Air flow is then directed
through dash panel to air distribution duct in passenger compartment.
On Durango, air taken from the front heater system is fed
back through an air duct into the center console. At the rear of the
center console, passengers can operate a 3 mode switch to adjust air
flow. Temperature and blower speeds are controlled by the front heater
control panel.
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.
OPERATION
HEATER CONTROL PANEL
Blower Motor Switch
Fan speed is controlled with a rotary blower motor switch.
There are 4 different fan speed settings: one low speed, 2 medium
speeds, and one high speed.
Mode Control Knob
A rotary mode switch is used to control air flow. There are 5
different modes of operation: panel, floor/panel, floor,
floor/defrost, and defrost.
Temperature Control Knob
Rotary control knob determines discharge air temperature by
positioning blend/air door. On Dakota and Durango, temperature blend-
air door is cable operated. On Ram Pickup and Ram Van/Wagon,
temperature blend-air door is electrically operated. When a hot
temperature is selected, all air flows through heater core.
ADJUSTMENTS
TEMPERATURE CONTROL CABLE ADJUSTMENT
Dakota & Durango
1) Ensure temperature control cable housing and core are
connected at both heater control panel and heater assembly. Ensure
heater control panel is properly installed.
2) Rotate temperature control knob so that knob pointer is at
12 o'clock position. Pull temperature control knob straight out from
heater control panel until perimeter of knob (not knob pointer)
protrudes about .25" (6 mm) from face of heater control panel.
3) Rotate temperature control knob clockwise so that knob

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.

4) To install, reverse removal procedure. Ensure heater
housing top cover seal, firewall and side cowl seals are in good
condition.
Fig. 7: Removing Radiator Support Assembly (Ram Van/Wagon)
Courtesy of Chrysler Corp.
HEATER CONTROL PANEL R & I
Removal & Installation (Dakota & Durango)
1) Disconnect negative battery cable. On models equipped with
A/T, unlock ignition switch. Set parking brake and place gear selector
lever in "L" position. If equipped, set tilt steering column in lowest
position.
2) On all models, carefully pry bezel away from instrument
panel to disengage clips. Unplug connectors from cigarette lighter and
auxiliary power outlet. Disconnect fog light switch (if equipped).
Remove 4 heater control panel bolts.
3) Pull control panel outward enough to disconnect wiring
connector, vacuum harness and temperature control cable. Remove heater
control panel. To install, reverse removal procedure. Adjust
temperature control cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT .
Removal & Installation (Ram Pickup)
1) Disconnect negative battery cable. Reach under driver's

side of instrument panel, near transmission tunnel, and unplug heater
control panel-to-heater assembly vacuum harness connector. Disconnect
vacuum harness from center air duct.
2) On models equipped with A/T, unlock ignition switch. Set
parking brake and place gear selector lever in "L" position. If
equipped, set tilt steering column in lowest position.
3) On all models, remove screw securing cluster bezel to
instrument panel. See Fig. 8. Carefully pry bezel away from instrument
panel to disengage clips. Unplug connectors from cigarette lighter and
auxiliary power outlet.
4) Remove 4 bolts attaching heater control panel. Pull
control panel outward enough to disconnect wiring connector and vacuum
harness. Remove heater control panel. To install, reverse removal
procedure.
Fig. 8: Removing Cluster Bezel (Ram Pickup)
Courtesy of Chrysler Corp.
CAUTION: Use care when removing or installing instrument cluster bezel
so as not to damage trip odometer reset button. If trip
odometer reset button is damaged, instrument cluster must be
replaced.
Removal & Installation (Ram Van/Wagon)
1) Disconnect negative battery cable. Remove engine cover
from passenger compartment. Reach between upper dash panel engine
housing extension and bottom of instrument panel. Disconnect vacuum
harness connector located near left defroster outlet of distribution
duct.
2) On models equipped with A/T, unlock ignition switch. Set
parking brake and place gear selector lever in "L" position. If
equipped, set tilt steering column in lowest position. Carefully pry
bezel away from instrument panel to disengage clips. Pull bezel away
far enough to clear trip odometer reset button. Remove bezel.
3) Remove 3 bolts from heater control panel. Pull heater
control panel outward enough to disconnect electrical connectors and

vacuum connector. Remove heater control panel. To install, reverse
removal procedure.
HEATER CORE
Removal & Installation
Remove heater assembly from vehicle. See HEATER ASSEMBLY.
Disable heater assembly and remove heater core.
INSTRUMENT PANEL
Removal & Installation (Dakota & Durango)
1) Disconnect negative battery cable. Disable air bag system.
See AIR BAG SYSTEM SAFETY article. Place front wheels in straight-
ahead position. Remove sill trim from both doorways. Remove kick panel
covers from both sides of vehicle. Remove mounting bolts for hood
release handle.
2) Remove steering column trim panel and support bracket. If
equipped, remove tilt steering column lever. Remove upper and lower
shrouds from steering column. Remove knee bolster. Unplug driver's
side air bag module. Loosen multifunction switch wiring harness
connector screw and disconnect from switch. Screw will remain in
connector.
3) Disconnect PRNDL cable. Disconnect shift cable from
steering column. Remove steering coupler lock pin. Remove toe plate
retaining bolts. Remove steering column mounting bolts and remove
steering column from vehicle.
4) Remove screw from bulkhead wiring harness connector and
disconnect. Disconnect 2 body wiring harness connectors located next
to bulkhead connector. Disconnect 3 wiring harness connectors located
nearest to dash panel from junction block. Disconnect brake light
switch. If equipped, disconnect Rear Wheel Anti-Lock (RWAL) brake
module, located near steering column support brackets.
5) Disconnect plastic retainer clip from parking brake
linkage rod, located at back of parking brake release handle. Remove
rod end from parking brake handle. Remove instrument panel center
support bracket. Unplug vacuum harness connector located at left end
of heater assembly housing. Disconnect Air Bag Control Module (ACM)
connector.
6) Remove glove box. Reach through glove box opening and
disconnect antenna coaxial cable. Disconnect blower motor connector
located above glove box opening, near support brace for heater
assembly housing. Disconnect radio ground strap. Loosen instrument
panel roll-own bracket bolts about 2 turns (bolts are located at lower
corners, on both sides of instrument panel). Remove 5 bolts across top
of dash panel, at base of windshield, removing center screw last.
7) Roll down instrument panel and install a temporary support
hook that is about 18" (457 mm) in length. Install hook from center
hole in instrument panel to center hole of dash panel. Pull lower
instrument panel outward until both roll-down bracket bolts are in
slotted roll-down position. Instrument panel should now be supported
and away from firewall.
8) Disconnect 2 body wiring harness connectors, located on a
bracket near right end of instrument panel. Disconnect blower motor
resistor. Disconnect temperature control cable from heater assembly
housing and remove from housing. Disconnect defrost duct flexible hose
from heater assembly housing.
9) Ensure all electrical and vacuum connectors are
disconnected and instrument panel is free and clear for removal. With
the aid of an assistant, remove temporary support hook. Lift
instrument panel off of roll-down bracket bolts and remove from
vehicle.
10) To install, reverse removal procedure. Ensure all wiring

and hoses are clear and not pinched. Adjusting temperature control
cable. See TEMPERATURE CONTROL CABLE ADJUSTMENT . Tighten bolts and
nuts to specification. See TORQUE SPECIFICATIONS. Enable air bag
system. See AIR BAG SYSTEM SAFETY article.
Removal & Installation (Ram Pickup)
1) Disconnect negative battery cable. Ensure front wheels are
in a straight-ahead position and steering wheel is in LOCKED position.
Disable air bag system. See AIR BAG SYSTEM SAFETY article. Remove Air
Bag Control Module (ACM) and bracket from floor panel transmission
tunnel. Drain cooling system.
2) Remove left and right cowl side inner trim panels. Remove
knee bolster/steering column cover. Remove hood release and parking
brake release handle bolts from lower instrument panel support.
3) Disconnect driver's side air bag connector at lower left
corner of instrument panel. If equipped, disconnect overdrive lock-out
switch wiring harness connector from instrument panel wire harness
near instrument panel lower reinforcement.
4) Pull PRNDL cable and twist to remove from position arm.
Push tab on bottom of cable retainer upward, then squeeze sides to
remove retainer from column. If equipped, remove tilt lever. Remove
both upper and lower shrouds from column. Remove lower fixed column
shroud. Loosen multifunction switch connector screw. Screw will remain
in connector.
5) Ensure steering wheel is in LOCKED position. Remove
remaining steering column electrical connectors. Remove air bag wiring
harness from steering column wiring trough. Remove wiring trough from
steering column. Remove steering column as an assembly from vehicle.
6) From driver's side of instrument panel, disengage parking
brake release linkage rod from parking brake mechanism. Disconnect
instrument panel wiring harness from parking brake mechanism.
Disconnect 3 wiring harness bulkhead connectors located closest to
dash panel.
7) Disconnect instrument panel left side wiring harness
connectors. Remove screw from center of headlight and dash-to-
instrument panel (bulkhead) connector, and disconnect connector.
Disconnect instrument panel-to-door wiring harness. Disconnect
instrument panel to stoplight switch connector. Disconnect vacuum
harness for heater system.
8) If equipped with an Infinity sound system, disconnect
Infinity wiring harness connector from instrument panel harness
connector that is secured to bulkhead connector.
9) From passenger's side of instrument panel, disconnect
radio antenna coaxial cable connector. Loosen right and left
instrument panel roll-down bracket bolts about .50" (13 mm). Removing
center screw last, remove 5 bolts holding top of instrument panel to
top of dash panel.
10) Roll instrument panel downward and install a temporary
support hook to center hole of dash panel. Support hook should support
instrument panel in rolled-down position, about 18" (457 mm) away from\
dash panel. Disconnect remaining wiring harness connectors. With the
aid of an assistant, remove temporary hook and lift instrument panel
from vehicle.
11) To install, reverse removal procedure. Ensure all wiring
and hoses are clear and not pinched. Tighten bolts and nuts to
specification. See TORQUE SPECIFICATIONS . Enable air bag system. See
AIR BAG SYSTEM SAFETY article.
TEMPERATURE CONTROL CABLE R & I
Removal (Dakota & Durango)
Disconnect negative battery cable. Disconnect but DO NOT
remove instrument panel. See INSTRUMENT PANEL. Disconnect temperature