service DODGE RAM 1999 Service Repair Manual

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.

1) Connect a vacuum gauge in line with Black heater vacuum
supply hose (located at tee near power brake booster, in engine
compartment). Position gauge so it can be viewed from passenger
compartment.
2) Start engine. While observing vacuum gauge, rotate mode
control knob to each mode position (one position at a time). Pause
after each selection. Vacuum gauge should drop then return to 8 in. Hg
shortly after each selection is made. If vacuum gauge reading is as
specified, go to next step. If gauge reading is not as specified,
check for vacuum leak in vacuum lines or 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. If temperature control knob does
not operate as specified, check condition, routing, installation and
adjustment of temperature control cable. See
TEMPERATURE CONTROL CABLE ADJUSTMENT.
HEATER OUTPUT
1) Start engine. Allow engine to reach normal operating
temperature. With engine at idle, set controls to maximum heat, floor
and high blower positions. Using a thermometer, check air temperature
coming from floor vents. See HEATER OUTPUT TEMPERATURE table.
2) If floor outlet air temperature is lower than specified,
check cooling system and electric cooling fan. See ELECTRIC COOLING
FAN article.
3) Check that both return and supply heater hoses are hot. If
coolant return hose is much cooler than supply hose, repair coolant
obstruction in heater system. Check for air flow obstruction in heater
system. Check blend air door for proper operation.
HEATER OUTPUT TEMPERATURE









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Ambient Temp. F (C) Outlet Vent Temp. F (C)
Except Durango
60 (15.6) ............................................. 144 (62.2\
)
70 (21.1) ............................................. 147 (63.8\
)
80 (26.6) ............................................. 150 (65.5\
)
90 (32.2) ............................................. 153 (67.2\
)
Durango
60 (15.6) ............................................. 126 (52.2\
)
70 (21.1) ............................................. 133 (56.1\
)
80 (26.6) ............................................. 139 (59.4\
)
90 (32.2) ............................................. 144 (62.2\
)









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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.
BLEND AIR DOOR MOTOR
Removal & Installation (Ram Pickup)
Remove heater assembly. See HEATER ASSEMBLY. Remove blend air

HO W T O U SE S YSTE M W IR IN G D IA G RAM S
1999 D odge P ic ku p R 1500
GENERAL INFORMATION
Using Wiring Diagrams
All Models
INTRODUCTION
This CD obtains wiring diagrams and technical service
bulletins, containing wiring diagram changes from the domestic and
import manufacturers. These are checked for accuracy and are all
redrawn into a consistent format for easy use.
In the past, when cars were simpler, diagrams were simpler.
All components were connected by wires and diagrams seldom exceeded 4
pages in length. Today, some wiring diagrams require more than 16
pages. It would be impractical to expect a service technician to trace
a wire from page 1 across every page to page 16.
Removing some of the wiring maze reduces eyestrain and time
wasted searching across several pages. Today the majority of
these

diagrams follow a much improved format, which permits space for
internal switch details.
Wiring diagrams are drawn in a "top-down" format. The
diagrams are drawn with the power source at the top of the diagram and
the ground point at the bottom of the diagram. Components locations
are identified on the wiring diagrams. Any wires that don't connect
directly to a component are identified on the diagram to indicate
where they go.
COLOR ABBREVIATIONS
COLOR ABBREVIATIONS TABLE








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Color Normal Optional
Black ................ BLK .......................... BK
Blue ................. BLU .......................... BU
Brown ................ BRN .......................... BN
Clear ................ CLR .......................... CR
Dark Blue .......... DK BLU ...................... DK BU
Dark Green ......... DK GRN ...................... DK GN
Green ................ GRN .......................... GN
Gray ................. GRY .......................... GY
Light Blue ......... LT BLU ...................... LT BU
Light Green ........ LT GRN ...................... LT GN
Orange ............... ORG .......................... OG
Pink ................. PNK .......................... PK
Purple ............... PPL .......................... PL
Red .................. RED .......................... RD
Tan .................. TAN .......................... TN
Violet ............... VIO .......................... VI
White ................ WHT .......................... WT
Yellow ............... YEL .......................... YL









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IDENTIFYING WIRING DIAGRAM ABBREVIATIONS
NOTE: Abbreviations used on these diagrams are normally
self-explanatory. If necessary see ABBREVIATIONS


IN STR UM EN T P A N EL - A N ALO G

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Analog Instrument Panels
Ram Pickup, Ram Van & Ram Wagon
DESCRIPTION & OPERATION
INSTRUMENT CLUSTER
All instrument cluster gauges are air core magnetic type.
Tachometer is optional. All gauges use data transferred on Chrysler
Collision Detection (CCD) bus. Instrument cluster incorporates a
Vacuum Fluorescent Display (VFD) for odometer display.
Brake warning light illuminates when ignition is on and
parking brake is applied. Brake warning light also illuminates if
brake hydraulic system failure occurs during service brake
application. Brake warning light bulb test occurs when ignition switch
is in START position.
Oil pressure warning light illuminates when engine oil
pressure is not sufficient to open oil pressure sending unit switch.
Oil pressure warning light bulb test occurs with ignition switch in
RUN position.
All instrument clusters include these analog gauges:
* Coolant Temperature Gauge
* Fuel Gauge
* Oil Pressure Gauge
* Speedometer
* Voltmeter
Instrument clusters include these indicator lights, if
vehicle is equipped with appropriate option:
* Air Bag
* Anti-Lock Brake System (ABS)
* Brake Warning
* Check Gauges
* Cruise On
* Headlight High Beam
* Low Fuel
* Low Washer Fluid
* CHECK ENGINE
* Overdrive Off
* Rear Wheel Anti-Lock (RWAL)
* Seat Belt Reminder
* Security
* Transmission Oil Temperature (A/T)
* Turn Signal
* Upshift (M/T)
* 4WD
SELF-DIAGNOSTIC SYSTEM
WARNING: Vehicle is equipped with an air bag system. To prevent air
bag deployment, disconnect negative battery cable and wait at
least 2 minutes before servicing instrument cluster. See
appropriate AIR BAG RESTRAINT SYSTEMS article.
CAUTION: When battery is disconnected, vehicle computer and memory

MAIN TE N AN CE IN FO RM ATIO N

1999 D odge P ic ku p R 1500
1997-99 MAINTENANCE
Chrysler Motors Maintenance Information
Dodge: Ram Pickup R1500
Ram Pickup R2500
Ram Pickup R3500
* PLEASE READ THIS FIRST *
Before preforming maintenance on vehicle, ensure that all
cautions and warnings have been observed to prevent vehicle damage or
personal injury. See CAUTIONS & WARNINGS.
NOTE: For scheduled maintenance intervals and the related fluid
capacities, fluid specifications and labor times for major
service intervals, see SCHEDULED SERVICES article below:
R1500
* SCHEDULED SERVICES - NORMAL SERVICE (GAS)
* SCHEDULED SERVICES - SEVERE SERVICE (GAS)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
R2500
* SCHEDULED SERVICES - NORMAL SERVICE (GAS)
* SCHEDULED SERVICES - SEVERE SERVICE (GAS)
* SCHEDULED SERVICES - NORMAL SERVICE (GAS - MD)
* SCHEDULED SERVICES - SEVERE SERVICE (GAS - MD)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
R3500
* SCHEDULED SERVICES - NORMAL SERVICE (GAS - MD)
* SCHEDULED SERVICES - SEVERE SERVICE (GAS - MD)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
* SCHEDULED SERVICES - NORMAL SERVICE (DIESEL)
Warranty information and specifications for fluid
capacities, lubrication specifications, wheel and tire size,
and battery type are covered in this article.
MODEL IDENTIFICATION
VIN LOCATION
The Vehicle Identification Number (VIN) is located on the
left side of the dash panel at the base of the windshield. The VIN
chart explains the code characters.
VIN CODE ID EXPLANATION

M * Lago Alberto, Mexico
12-17 - Serial Number
* Sequential Production Number
MAINTENANCE SERVICE INFORMATION
LIGHT & HEAVY DUTY SERVICE DEFINITIONS
Maintenance service is recommended at different mileage
intervals based on Gross Vehicle Weight Rating (GVWR). See appropriate\
SERVICE SCHEDULES article.
Light Duty
Vehicles with GVWR of 8500 lbs. or less.
Heavy Duty
Vehicles with GVWR of 8501 lbs. or more.
SEVERE & NORMAL SERVICE DEFINITIONS
Service is recommended at mileage intervals based on vehicle
operation. Normal Service and Severe Service schedules are based on
the following primary operating conditions:
Normal Service
* Driven More Than 10 Miles Daily
* NO Severe Service Operating Conditions
Severe Service
NOTE: Use the Severe Service schedule if the vehicle to be serviced
is operated under ANY (one or more) of these conditions:
* Frequent Short Trips Of Less than 5 Miles (8 KM)
* Frequent Driving In Dusty Conditions
* Frequent Trailer Towing
* Frequent Idling
* More Than 50% Of Your Driving Is At Sustained High Speeds
During Hot Weather, Above 90
\bF (32\bC)
SERVICE POINT LOCATIONS

Fig. 1: Service Point Locations (Typical V6 and V8 Engines)
Courtesy of Chrysler Corp.
Fig. 2: Service Point Locations (8.0L V10 Engine)
Courtesy of Chrysler Corp.

Fig. 3: Service Point Locations (5.9L Turbo-Diesel)
Courtesy of Chrysler Corp.
ADDITIONAL SERVICE INFORMATION - DIESEL MODELS

Fig. 4: Engine Service Locations (5.9L Engine - Diesel)
Courtesy of Chrysler Corp.
NOTE: For more information regarding 5.9L Diesel engine service
refer to the E - THEORY/OPERATION - 5.9L DIESEL article