1998 DODGE RAM 1500 tire type

(7) Reinstall both wiper arms onto the wiper piv-
ots. (Refer to 8 - ELECTRICAL/WIPERS/WASHERS/
WIPER ARM - INSTALLATION).
WASHER PUMP/MOTOR
DESCRIPTION
The washer pump/motor unit (Fig. 12) is located on
the rearward facing surface of the washer reservoir,
in the right (except diesel engine) or left (diesel
engine only) front corner of the engine compartment.
A small permanently lubricated and sealed electric
motor is coupled to the rotor-type washer pump. A
seal flange with a barbed inlet nipple on the pump
housing passes through a rubber grommet seal
installed in a dedicated mounting hole of the washer
reservoir. When the pump is installed in the reser-
voir a barbed outlet nipple on the pump housing con-
nects the unit to the washer system through a short
washer reservoir hose.
The washer pump/motor unit is retained on the
reservoir by the interference fit between the barbed
pump inlet nipple and the grommet seal, which is a
light press fit. The top of the washer pump is also
secured to the washer reservoir by the use of a snappost on the motor housing and a snap post receptacle
molded into the reservoir that allows for mounting of
the washer pump without the use of fasteners. An
integral connector receptacle on the top of the motor
housing connects the unit to the vehicle electrical
system. The washer pump/motor unit cannot be
repaired. If faulty or damaged, the entire washer
pump/motor unit must be replaced.
OPERATION
The washer pump/motor unit features a small
Direct Current (DC) electric motor. The motor is con-
nected to the vehicle electrical system through a sin-
gle take out and two-cavity connector of the right
(except diesel engine) or left (diesel engine only)
headlamp and dash wire harness. The motor is
grounded at all times through another take out of
the right (except diesel engine) or left (diesel engine
only) headlamp and dash wire harness. On models
without the diesel engine, a single eyelet terminal
connector is secured by a nut to a ground stud
located on the right front fender inner shield in the
engine compartment. On models with a diesel engine,
an eyelet terminal connector is secured by a ground
screw to the left front fender inner shield in the
engine compartment. The motor receives battery cur-
rent on a washer pump/motor control circuit.
The washer pump/motor control circuit is energized
through a high side driver within the Front Control
Module (FCM) whenever the FCM receives an elec-
tronic message requesting washer system operation
from the instrument cluster over the Programmable
Communications Interface (PCI) data bus. The
instrument cluster monitors a resistor multiplexed
hard wired input from the momentary washer switch
contacts within the multi-function switch on the
steering column to determine when it should issue
the electronic message requesting washer system
operation.
Washer fluid is gravity-fed from the washer reser-
voir to the inlet side of the washer pump. When the
pump motor is energized, the motor spins the rotor
within the washer pump. The spinning pump rotor
pressurizes the washer fluid and forces it through
the pump outlet nipple, the washer plumbing, and
the washer nozzles onto the windshield glass.
The washer pump/motor unit may be diagnosed
using conventional diagnostic tools and methods.
However, conventional diagnostic methods may not
prove conclusive in the diagnosis of the instrument
cluster, the FCM, or the electronic message inputs to
or outputs from the instrument cluster and the FCM
that control the operation of the washer pump/motor
unit. The most reliable, efficient, and accurate means
to diagnose the washer pump/motor unit, the instru-
ment cluster, the FCM, or the electronic message
Fig. 12 Washer Pump/Motor
1 - MOTOR
2 - SNAP POST
3 - CONNECTOR RECEPTACLE
4 - PUMP
5 - OUTLET NIPPLE
6 - INLET NIPPLE
7 - FILTER SCREEN
DRWIPERS/WASHERS 8R - 13
WASHER NOZZLE (Continued)

INSTALLATION
(1) Position the wiper high/low relay to the proper
receptacle in the Integrated Power Module (IPM)
(Fig. 24).
(2) Align the wiper high/low relay terminals with
the terminal cavities in the IPM receptacle.
(3) Push firmly and evenly on the top of the wiper
high/low relay until the terminals are fully seated in
the terminal cavities in the IPM receptacle.
(4) Reinstall the cover onto the IPM.
(5) Reconnect the battery negative cable.
WIPER MODULE
DESCRIPTION
The wiper motor bracket is secured with two
screws below the wiper motor through two rubber
insulators to the bottom of the cowl plenum panel
beneath the cowl plenum cover/grille panel (Fig. 25).
Two screws secure the top of the wiper module
bracket to the cowl plenum panel through rubber
insulators located on the outboard end of each pivot
bracket. The ends of the wiper pivot shafts that pro-
trude through dedicated openings in the cowl plenum
cover/grille panel to drive the wiper arms and bladesare the only visible components of the wiper module.
The wiper module consists of the following major
components:
²Bracket- The wiper module bracket consists of
a long tubular steel main member that has a die cast
pivot bracket formation near each end where the two
wiper pivots are secured. A stamped steel clamp
secures the center of the tubular member to the die
cast bracket integral to the wiper motor with two
screws.
²Crank Arm- The wiper motor crank arm is a
stamped steel unit with a slotted hole on the driven
end that is secured to the wiper motor output shaft
with a nut, and has a ball stud secured to the drive
end.
²Linkage- Two stamped steel drive links con-
nect the wiper motor crank arm to the wiper pivot
lever arms. The left side drive link has a plastic sock-
et-type bushing on each end. The right side drive
link has a plastic socket-type bushing on one end,
and a plastic sleeve-type bushing on the other end.
The socket-type bushing on one end of each drive
link is snap-fit over the ball stud on the lever arm of
its respective pivot. The right side drive link sleeve-
type bushing end is then fit over the motor crank
arm ball stud, and the other socket-type bushing of
the left side drive link is snap-fit over the exposed
end of the wiper motor crank arm ball stud.
²Motor- The wiper motor features an integral
die cast bracket to which the wiper module bracket is
secured with a stamped steel clamp and two screws
near the top and which has two rubber insulated
mounting ears at the bottom. This die casting also
serves as the wiper motor transmission housing from
which the wiper motor output shaft exits. A nut
secures the wiper motor crank arm to the motor out-
put shaft. The two-speed permanent magnet wiper
motor features an integral transmission, an internal
park switch, and an internal automatic resetting cir-
cuit breaker.
²Pivots- The two front wiper pivots are secured
within the die cast pivot brackets on the outboard
ends of the wiper module main member. The lever
arms that extend from the center of the pivot shafts
each have a ball stud on their end. The upper end of
each pivot shaft where the wiper arms will be fas-
tened each has a serrated driver with a keyway. The
lower ends of the pivot shafts are installed through
lubricated bushings in the pivot brackets and are
secured with snap rings.
The wiper module cannot be adjusted or repaired.
If any component of the module is faulty or damaged,
the entire wiper module unit must be replaced.
Fig. 25 Wiper Module
1 - PIVOT BRACKET (2)
2 - TUBE
3 - CLAMP
4 - PIVOT SHAFT (2)
5 - INSULATOR (4)
6 - LINKAGE BUSHING (4)
7 - DRIVE LINK (2)
8 - PIVOT CRANK ARM (2)
9 - PIGTAIL WIRE CONNECTOR
10 - MOTOR CRANK ARM
11 - WIPER MOTOR
8R - 22 WIPERS/WASHERSDR
WIPER HIGH/LOW RELAY (Continued)

WIRE
STANDARD PROCEDURE - WIRE SPLICING
When splicing a wire, it is important that the cor-
rect gage be used as shown in the wiring diagrams.
(1) Remove one-half (1/2) inch of insulation from
each wire that needs to be spliced.
(2) Place a piece of adhesive lined heat shrink tub-
ing on one side of the wire. Make sure the tubing will
be long enough to cover and seal the entire repair
area.
(3) Place the strands of wire overlapping each
other inside of the splice clip (Fig. 14).
(4) Using crimping tool, Mopar p/n 05019912AA,
crimp the splice clip and wires together (Fig. 15).(5) Solder the connection together using rosin core
type solder only (Fig. 16).
CAUTION: DO NOT USE ACID CORE SOLDER.
(6) Center the heat shrink tubing over the joint
and heat using a heat gun. Heat the joint until the
tubing is tightly sealed and sealant comes out of both
ends of the tubing (Fig. 17).
Fig. 14 SPLICE BAND
1 - SPLICE BAND
Fig. 15 CRIMPING TOOL
1 - CRIMPING TOOL
Fig. 16 SOLDER SPLICE
1 - SOLDER
2 - SPLICE BAND
3 - SOLDERING IRON
Fig. 17 HEAT SHRINK TUBE
1 - SEALANT
2 - HEAT SHRINK TUBE
DR8W-01 WIRING DIAGRAM INFORMATION 8W - 01 - 15

(8) Torque the (3) bolts that attach the front axle
to the left engine bracket to 101 N´m (75 ft. lbs.).
(9) Install the engine oil filter, if removed.
(10) Install the front crossmember(Refer to 13 -
FRAME & BUMPERS/FRAME/FRONT CROSS-
MEMBER - INSTALLATION).
(11) Install the skid plate.
(12) Lower the vehicle.
(13) Reconnect the negative battery cable.
REAR MOUNT
REMOVAL
(1) Raise the vehicle on a hoist.
(2) Using a suitable jack, support transmission.
(3) Remove the nuts from the transmission mount
(Fig. 26).
(4) Remove the two bolts that attach the transmis-
sion mount to the engine bracket.
(5) Raise the transmission enough to remove the
mount from the crossmember.
(6) Remove the mount.
INSTALLATION
NOTE: Threadlocking compound must be applied to
the bolts before installation.(1) Install the two bolts that attach the transmis-
sion mount to the transmission bracket.
(2) Torque the bolts to 61N´m (45 ft.lbs.) torque.
(3) Lower the transmission so the transmission
mount rests on the crossmember, and the studs of
the transmission mount are aligned in the slots in
the crossmember.
(4) Install the nuts onto the transmission mount
studs through the crossmember access slot.
(5) Torque the nuts to 54N´m (40 ft. lbs.).
LUBRICATION
DESCRIPTION
The lubrication system (Fig. 27) is a full flow fil-
tration pressure feed type.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - CHECKING
ENGINE OIL PRESSURE
(1) Remove oil pressure sending unit and install
gauge assembly C-3292.
(2) Run engine until thermostat opens.
(3) Oil Pressure:
²Curb Idle±25 kPa (4 psi) minimum
²3000 rpm±170 - 758 kPa (25 - 110 psi)
(4) If oil pressure is 0 at idle, shut off engine.
Check for a clogged oil pick-up screen or a pressure
relief valve stuck open.
DIAGNOSIS AND TESTING - ENGINE OIL LEAK
Begin with a thorough visual inspection of the
engine, particularly at the area of the suspected leak.
If an oil leak source is not readily identifiable, the
following steps should be followed:
(1) Do not clean or degrease the engine at this
time because some solvents may cause rubber to
swell, temporarily stopping the leak.
(2) Add an oil soluble dye (use as recommended by
manufacturer). Start the engine and let idle for
approximately 15 minutes. Check the oil dipstick to
make sure the dye is thoroughly mixed as indicated
with a bright yellow color under a black light.
(3) Using a black light, inspect the entire engine
for fluorescent dye, particularly at the suspected area
of oil leak. If the oil leak is found and identified,
repair per service manual instructions.
(4) If dye is not observed, drive the vehicle at var-
ious speeds for approximately 24 km (15 miles), and
repeat inspection.If the oil leak source is not pos-
itively identified at this time, proceed with the air
leak detection test method.
Fig. 26 TRANSMISSION MOUNT
1 - MOUNT
2 - CROSSMEMBER
3 - NUT
4 - BOLT
9 - 220 ENGINE - 5.7LDR
FRONT MOUNT (Continued)

(9) Remove the clip and remove the spare tire
winch tube. (Fig. 21)
(10) Remove the bolts and remove the spare tire
winch. (Fig. 22)
(11) Position the wire harness forward of the work
area.
CAUTION: Do not use any flame or plasma cutting
equipment to cut the frame in this procedure. The
inaccurate and high temperatures achieved during
flame or plasma cutting will change the metal char-
acteristics and may weaken the frame and/or repair
location.(12) Carefully remove the H-section welds using a
grinder or equivalent tool.
(13) Remove the H-section and clean any remain-
ing welds from the frame.
(14) Trial fit the replacement part.
(15) Remove all e-coat from within 25 mm (1.0 in.)
of the weld area.
(16) Using the appropriate measuring equipment,
position the replacement part and verify correct posi-
tioning in all three (X,Y, and Z) planes of space.
(Refer to 13 - FRAME & BUMPERS/FRAME - SPEC-
IFICATIONS - FRAME DIMENSIONS)
CAUTION: Shield the surrounding area and compo-
nents from exposure to the welding spatter and
heat.
(17) Weld the replacement H-section into position.
The welding should be performed in a skip (stitch)
type method to minimize the heat buildup following
I-CAR or the American Welding Society welding pro-
cedures and utilizing the process specifications at the
end of this section. (Refer to 13 - FRAME &
BUMPERS/FRAME - SPECIFICATIONS - WELD-
ING)
(18) Dress the welded area and apply corrosion
resistant coatings inside and out.
(a) Inside the rail, inject a creeping wax based
rust inhibitor compound through the existing holes
in the frame ensuring 100% coverage including the
mating face between the frame and replacement
H-section.
(b) Apply a durable top coat to the outside of the
repair area.
(19) Position the wiring harness back.
CAUTION: Inspect the tire winch assembly for dam-
age. If any one or more of the following are evident,
replace the winch assembly.
²Indications of cracked or bulging plastic.
²Housing flanges are bent or cracked.
²If winch was loose before repair.
(20) Install the spare tire winch and install the
bolts. (Fig. 22)
(21) Tighten the bolts to 41 N´m (30 ft. lbs.).
(22) Install the spare tire winch tube and install
the clip. (Fig. 21)
(23) Install the spare tire.
CAUTION: Check operation of the spare tire winch
by manipulating it up and down. If the winch binds
or jambs, replace the winch assembly.
(24) Lift the axle into position and install the rear
shackle bolts. (Fig. 20)
(25) Tighten the bolts to 163 N´m (120 ft. lbs.).
Fig. 21 SPARE TIRE WINCH TUBE
1 - SPARE TIRE WINCH ASSEMBLY
2 - HAIR PIN CLIP
3 - WINCH TUBE
4 - H-SECTION/SPARE WHEEL SUPPORT
Fig. 22 SPARE TIRE WINCH ASSEMBLY
1 - SPARE TIRE WINCH ASSEMBLY
2 - BOLTS
3 - RETAINER BRACKET
4 - H-SECTION/SPARE WHEEL SUPPORT
13 - 14 FRAMES & BUMPERSDR
FRAME (Continued)

TIRES
DESCRIPTION
DESCRIPTION - SPARE TIRE / TEMPORARY
The temporary spare tire is designed for emer-
gency use only. The original tire should be repaired
or replaced at the first opportunity, then reinstalled.
Do not exceed speeds of 50 M.P.H. when using the
temporary spare tire. Refer to Owner's Manual for
complete details.
DESCRIPTION - TIRES
Tires are designed and engineered for each specific
vehicle. They provide the best overall performance
for normal operation. The ride and handling charac-
teristics match the vehicle's requirements. With
proper care they will give excellent reliability, trac-
tion, skid resistance, and tread life.
Driving habits have more effect on tire life than
any other factor. Careful drivers will obtain in most
cases, much greater mileage than severe use or care-
less drivers. A few of the driving habits which will
shorten the life of any tire are:
²Rapid acceleration
²Severe brake applications
²High speed driving
²Excessive speeds on turns
²Striking curbs and other obstacles
Radial-ply tires are more prone to irregular tread
wear. It is important to follow the tire rotation inter-
val shown in the section on Tire Rotation, (Refer to
22 - TIRES/WHEELS - STANDARD PROCEDURE).
This will help to achieve a greater tread life.
TIRE IDENTIFICATION
Tire type, size, aspect ratio and speed rating are
encoded in the letters and numbers imprinted on the
side wall of the tire. Refer to the chart to decipher
the tire identification code (Fig. 11).
Performance tires have a speed rating letter after
the aspect ratio number. The speed rating is not
always printed on the tire sidewall. These ratings
are:
²Qup to 100 mph
²Rup to 106 mph
²Sup to 112 mph
²Tup to 118 mph
²Uup to 124 mph
²Hup to 130 mph
²Vup to 149 mph
²Zmore than 149 mph (consult the tire manu-
facturer for the specific speed rating)An All Season type tire will have eitherM+S,M
&SorM±S(indicating mud and snow traction)
imprinted on the side wall.
TIRE CHAINS
Tire snow chains may be used oncertainmodels.
Refer to the Owner's Manual for more information.
DESCRIPTION - RADIAL ± PLY TIRES
Radial-ply tires improve handling, tread life and
ride quality, and decrease rolling resistance.
Radial-ply tires must always be used in sets of
four. Under no circumstances should they be used on
the front only. They may be mixed with temporary
spare tires when necessary. A maximum speed of 50
MPH is recommended while a temporary spare is in
use.
Radial-ply tires have the same load-carrying capac-
ity as other types of tires of the same size. They also
use the same recommended inflation pressures.
The use of oversized tires, either in the front or
rear of the vehicle, can cause vehicle drive train fail-
ure. This could also cause inaccurate wheel speed
signals when the vehicle is equipped with Anti-Lock
Brakes.
The use of tires from different manufactures on the
same vehicle is NOT recommended. The proper tire
pressure should be maintained on all four tires.
Fig. 11 Tire Identification
22 - 6 TIRES/WHEELSDR

spikes and electromagnetic interference that can be
generated as the electromagnetic field of the relay
coil collapses.
The A/C compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the integrated power module (IPM). The
inputs and outputs of the A/C compressor clutch
relay include:
²The common feed terminal (30) receives a bat-
tery current input from a fuse in the IPM through a
fused B(+) circuit at all times.
²The coil ground terminal (86) receives a ground
input from the PCM/ECM through the A/C compres-
sor clutch relay control circuit only when the PCM/
ECM electronically pulls the control circuit to
ground.
²The coil battery terminal (85) receives a battery
current input from PTC 1 in the IPM through a
fused ignition switch output (run) circuit only when
the ignition switch is in the On position.
²The normally open terminal (87) provides a bat-
tery current output to the compressor clutch coil
through the A/C compressor clutch relay output cir-
cuit only when the A/C compressor clutch relay coil is
energized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the A/C compres-
sor clutch relay coil is de-energized.
Refer to the appropriate wiring information for
diagnosis and testing of the micro-relay and for com-
plete HVAC wiring diagrams.
REMOVAL
(1) Disconnect and isolate the negative battery
cable.
(2) Remove the cover from the integrated power
module (IPM) (Fig. 11).
(3) Refer to the fuse and relay layout label on the
IPM cover for compressor clutch relay identification
and location.
(4) Remove the A/C compressor clutch relay from
the IPM.
INSTALLATION
(1) See the fuse and relay layout label affixed to
the underside of the IPM cover for A/C compressor
clutch relay location.
(2) Position the A/C compressor clutch relay in the
proper receptacle in the IPM.
(3) Align the A/C compressor clutch relay termi-
nals with the terminal cavities in the IPM receptacle.
(4) Push down firmly on the A/C compressor clutch
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install the cover onto the IPM.(6) Reconnect the negative battery cable.
A/C HEATER CONTROL
DESCRIPTION
The heater and air conditioning systems use elec-
trical controls. These controls provide the vehicle
operator with a number of setting options to help
control the climate and comfort within the vehicle.
The A/C-heater control for the Single Zone system
(Fig. 12) or Dual Zone system (Fig. 13) is located to
the right of the instrument cluster on the instrument
panel.
The Single Zone control panel contains a rotary-
type temperature control switch, a rotary-type mode
control switch and a rotary-type blower motor speed
switch. The A/C-heater control also has a push but-
ton to activate the optional heated side view mirror
defroster elements and to turn the A/C on.
The Dual Zone control panel contains a pair of slid-
er-type temperature control switches, a rotary-type
mode control switch and a rotary-type blower motor
speed switch. The control also has buttons to activate
the optional heated sideview mirror defroster ele-
ments, turn the A/C on and set the system to Max
A/C.
The A/C-heater control panel cannot be repaired. If
faulty or damaged, the entire unit must be replaced.
Fig. 11 Integrated Power Module (IPM)
1 - BATTERY
2 - INTEGRATED POWER MODULE (IPM)
24 - 14 CONTROLSDR
A/C COMPRESSOR CLUTCH RELAY (Continued)

BLOWER MOTOR SWITCH
DESCRIPTION
The blower motor is controlled by a rotary-type
blower motor switch, mounted in the A/C-heater con-
trol. The switch allows the selection of one of four
different blower motor speeds and includes an Off
position.
OPERATION
The blower motor switch provides a blower motor
ground path through the A/C-heater mode control
switch. The blower motor switch directs this ground
path through or around the blower motor resistor
wires, as required to achieve the selected blower
motor speed.
The blower motor switch cannot be repaired and, if
faulty or damaged, the entire A/C-heater control
must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
SWITCH
For circuit descriptions and diagrams, refer to the
appropriate wiring information. The wiring informa-
tion includes wiring diagrams, proper wire and con-
nector repair procedures, further details on wire
harness routing and retention, as well as pin-out and
location views for the various wire harness connec-
tors, splices and grounds.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Check for battery voltage at the fuse in the
Power Distribution Center (PDC). If OK, go to Step
2. If not OK, repair the shorted circuit or component
as required and replace the faulty fuse.
(2) Turn the ignition switch to the Off position.
Disconnect and isolate the battery negative cable.
Remove the A/C-heater control from the instrument
panel (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS/A/C HEATER CONTROL -
REMOVAL). Check for continuity between the
ground circuit cavity of the A/C-heater control wire
harness connector and a good ground. There should
be continuity. If OK, go to Step 3. If not OK, repair
the open circuit to ground as required.
(3) With the A/C-heater control wire harness con-
nector disconnected, place the A/C-heater mode con-
trol switch in any position except the Off position.
Check for continuity between the ground circuit ter-
minal and each of the blower motor driver circuit ter-
minals of the A/C-heater control as you move the
blower motor switch to each of the four speed posi-
tions. There should be continuity at each driver cir-
cuit terminal in only one blower motor switch speed
position. If OK, test and repair the blower driver cir-
cuits between the A/C-heater control connector and
the blower motor resistor as required. If not OK,
replace the faulty A/C-heater control.
DEFROST DOOR ACTUATOR
DESCRIPTION
The defrost door actuator is a reversible, 12-volt
Direct Current (DC), servo motor. The defrost door
actuator is located on the driver side end of the
HVAC housing, underneath the instrument panel
and is mechanically connected to the defroster door.
The defrost door actuator is interchangeable with
the actuators for the mode door, blend door(s) and
the recirculation door. Each actuator is contained
within an identical black molded plastic housing with
an integral wire connector receptacle. Integral
mounting tabs allow the actuator to be secured with
three screws to the HVAC housing. Each actuator
also has an identical output shaft with splines that
connects it to the linkage that drives the proper door.
The defrost door actuator does not require mechani-
Fig. 18 A/C-Heater Control - Single Zone Shown,
Dual Zone Typical
1 - MOUNTING TAB (4)
2 - A/C BUTTON
3 - SIDEVIEW MIRROR DEFROSTER BUTTON (IF EQUIPED)
4 - MODE CONTROL SWITCH
5 - TEMPERATURE CONTROL SWITCH
6 - BLOWER MOTOR SWITCH
24 - 20 CONTROLSDR