1998 DODGE RAM 1500 heater

POWERTRAIN CONTROL MODULE C2 (NGC) - ORANGE 38 WAY
CAV CIRCUIT FUNCTION
1 K10 18DB/OR COIL CONTROL NO. 6
2 K16 18DB/YL COIL CONTROL NO. 5
3 K15 18DB/GY COIL CONTROL NO. 4
4 K58 18BR/VT INJECTOR CONTROL NO. 6
5 K38 18BR/OR INJECTOR CONTROL NO. 5
6 K447 18TN/YL (5.7L) ETC MOTOR (+)
7 K18 18DB/OR COIL CONTROL NO. 3
8 K35 18DB/VT (5.7L LIGHT DUTY) EGR SOLENOID CONTROL
9 K17 18DB/TN COIL CONTROL NO. 2
10 K19 18DB/DG COIL CONTROL NO. 1
11 K14 18BR/TN INJECTOR CONTROL NO. 4
12 K13 18BR/LB INJECTOR CONTROL NO. 3
13 K12 18BR/DB INJECTOR CONTROL NO. 2
14 K11 18BR/YL INJECTOR CONTROL NO. 1
15 K922 18BR/DB (5.7L) THROTTLE POSITION SENSOR GROUND
16 - -
17 K199 18BR/VT O2 2/1 HEATER CONTROL
18 K99 18BR/LG O2 1/1 HEATER CONTROL
19 K20 18BR/GY GEN FIELD CONTROL
20 K2 18VT/OR ECT SIGNAL
21 K22 18BR/OR TP NO. 1 SIGNAL
22 K34 18DB/LG (5.7L LIGHT DUTY) EGR SENSOR SIGNAL
23 K1 18VT/BR MAP SIGNAL
24 K942 18BR/LG (EXCEPT 4.7L) KNOCK SENSOR NO. 1 RETURN
25 K42 18DB/YL (EXCEPT 4.7L) KNOCK SENSOR NO. 1 SIGNAL
26 - -
27 K900 18DB/DG SENSOR GROUND
28 K122 18BR/DG (5.7L) TP NO. 2 SIGNAL
28 K961 18BR/VT (EXCEPT 5.7L) IAC RETURN
29 F855 18PK/YL 5 VOLT SUPPLY
30 K21 18DB/LG IAT SIGNAL
31 K41 18DB/LB O2 1/1 SIGNAL
32 K904 18DB/DG O2 RETURN (DOWN)
33 K43 18DB/LG O2 2/1 SIGNAL
34 K44 20DB/GY CMP SIGNAL
35 K24 20BR/LB CKP SIGNAL
36 K242 18BR/WT (EXCEPT 4.7L) KNOCK SENSOR NO. 2 SIGNAL
37 K924 18WT/BR (EXCEPT 4.7L) KNOCK SENSOR NO. 2 RETURN
38 K448 18TN/OR (5.7L) ETC MOTOR (-)
38 K61 18VT/GY (EXCEPT 5.7L) IAC MOTOR CONTROL
DR8W-80 CONNECTOR PIN-OUTS 8W - 80 - 89

POWERTRAIN CONTROL MODULE C3 (NGC) - WHITE 38 WAY
CAV CIRCUIT FUNCTION
1- -
2- -
3 K51 20BR/WT ASD RELAY CONTROL
4- -
5 V35 20VT/OR (4.7L) S/C VENT CONTROL
6 K173 18BR/VT CONDENSER FAN RELAY CONTROL
7 V32 20VT/YL (4.7L) S/C POWER SUPPLY
8 K106 18VT/LB NVLD SOLENOID CONTROL
9 K299 18BR/WT O2 1/2 HEATER CONTROL
10 K399 18BR/GY O2 2/2 HEATER CONTROL
11 C13 20LB/OR A/C CLUTCH RELAY CONTROL
12 V36 20VT/YL (4.7L) S/C VACUUM CONTROL
13 - -
14 V32 20VT/YL (5.7L) BRAKE SWITCH NO. 2 SIGNAL
15 V937 20VT/BR (5.7L) S/C SWITCH RETURN
16 K167 20BR/YL (5.7L) APPS NO. 1 RETURN
17 K400 20BR/VT (5.7L) APPS NO. 2 RETURN
18 V38 20VT/OR (5.7L) S/C SWITCH NO. 2 SIGNAL
19 K342 16BR/WT ASD RELAY OUTPUT
20 K52 18DB/WT EVAP PURGE CONTROL
21 T41 20YL/DB TRS T41 SENSE
22 G113 18VT PTO SWITCH SENSE
23 B29 20DG/WT BRAKE SWITCH SIGNAL
24 - -
25 K23 20BR/WT (5.7L) APPS NO. 1 SIGNAL
26 - -
27 - -
28 K342 16BR/WT ASD RELAY OUTPUT
29 K70 18DB/BR EVAP PURGE RETURN
30 K66 18DB/WT P/S SWITCH SIGNAL
31 - -
32 K25 18DB/VT BATT TEMP SIGNAL
33 N4 18DB/WT (3.7L/4.7L) FUEL LEVEL SENSOR SIGNAL
33 N4 20DB/WT (5.7L) FUEL LEVEL SENSOR SIGNAL
34 V37 20VT S/C SWITCH NO. 1 SIGNAL
35 K107 18VT/WT NVLD SWITCH SIGNAL
36 K29 20WT/BR (5.7L) APPS NO. 2 SIGNAL
37 K31 20BR FUEL PUMP RELAY CONTROL
38 T752 20DG/OR STARTER RELAY CONTROL
8W - 80 - 90 8W-80 CONNECTOR PIN-OUTSDR

SEAT BELT SWITCH-DRIVER-2WAY
CAV CIRCUIT FUNCTION
1 Z951 20BK GROUND
2 G10 20VT/LG SEAT BELT SWITCH SENSE
SEAT BELT TENSIONER REDUCER (STANDARD CAB)-2WAY
CAV CIRCUIT FUNCTION
1 F983 20PK/YL FUSED IGNITION SWITCH OUTPUT (RUN-ACC)
2 G10 20VT/LG SEAT BELT SWITCH SENSE
SEAT BELT TENSIONER-DRIVER-2WAY
CAV CIRCUIT FUNCTION
1 R55 20LG/DG DRIVER SEAT BELT TENSIONER LINE 1
2 R53 20LG/YL DRIVER SEAT BELT TENSIONER LINE 2
SEAT BELT TENSIONER-PASSENGER-2WAY
CAV CIRCUIT FUNCTION
1 R54 20LB/YL PASSENGER SEAT BELT TENSIONER LINE 2
2 R56 20LB/DG PASSENGER SEAT BELT TENSIONER LINE 1
SEAT HEATER INTERFACE MODULE - GREEN 14 WAY
CAV CIRCUIT FUNCTION
1 P7 20LG/DG DRIVER SEAT HEATER MUX SWITCH
2 P89 20LG/OR SEAT HEATER DRIVER
3 P188 18LG/VT PASSENGER SEAT TEMPERATURE SENSOR INPUT
4 A930 18RD FUSED B(+)
5 P187 18LG/BR DRIVER SEAT TEMPERATURE SENSOR INPUT
6 A930 18RD FUSED B(+)
7 P54 20OR/LG PASSENGER SEAT TEMPERATURE 5 VOLT SUPPLY
8 P53 20LG/OR DRIVER SEAT TEMPERATURE 5 VOLT SUPPLY
9 P8 20LG/WT PASSENGER SEAT HEATER MUX SWITCH
10 P82 20TN/DG PASSENGER SEAT LOW HEAT LED DRIVER
11 P84 20TN/VT PASSENGER SEAT HIGH HEAT LED DRIVER
12 P81 20TN/LB DRIVER SEAT LOW HEAT LED DRIVER
13 Z951 20BK GROUND
14 P83 20TN/WT DRIVER SEAT HIGH HEAT LED DRIVER
8W - 80 - 94 8W-80 CONNECTOR PIN-OUTSDR

8W-91 CONNECTOR/GROUND/SPLICE LOCATION
TABLE OF CONTENTS
page
CONNECTOR/GROUND/SPLICE LOCATION
DESCRIPTION..........................1
CONNECTOR/GROUND/SPLICE
LOCATION
DESCRIPTION
This section provides illustrations identifying con-
nector, ground, and splice locations in the vehicle.
Connector, ground, and splice indexes are provided.Use the wiring diagrams in each section for connec-
tor, ground, and splice identification. Refer to the
index for the proper figure number. For items that
are not shown in this section N/S is placed in the
Fig. column.
CONNECTORS
CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
4WD Switch (Manual Transfer
Case)BK Near T/O for Backup Lamp Switch 16, 17, 19
A/C Compressor Clutch BK At A/C Compressor 3, 6, 7, 10
A/C Pressure Transducer BK Left Side of A/C Compressor 6, 7, 10
A/C-Heater Control C1 BK Center of Instrument Panel 34, 35, 36
A/C-Heater Control C2 BK Center of Instrument Panel 34, 35
Accelerator Pedal Position Sensor Under Battery Tray 22, 27
Adjustable Pedal Motor WT Left of Instrument Panel 31
Adjustable Pedal Switch BL Left of Instrument Panel 35, 38
Airbag Control Module C1 YL Lower Center of Instrument Panel 35, 36
Airbag Control Module C2 YL Lower Center of Instrument Panel 44, 46
Airbag Control Module-Left Side
ImpactYL Left B-Pillar 44, 46
Airbag Control Module-Right Side
ImpactYL Right B-Pillar 45, 47
Airbag-Driver Squib 1 YL On Steering Wheel N/S
Airbag-Left Curtain YL Top Left B-Pillar 44, 46
Airbag-Passenger YL Right Front of Instrument Panel 35, 39
Airbag-Right Curtain YL Top Right B-Pillar 45, 47
Ambient Temperature Sensor BK Left Rear of Hood 23, 29
Amplifier Audio C1 GY Top Center of Instrument Panel 35, 39
Amplifier Audio C2 GY Top Center of Instrument Panel 35, 39
Ashtray Lamp Center Stack 35
Automatic Day/Night Mirror (Except
Base)BK Top Center of Windshield N/S
Backup Lamp Switch BK Left Rear of Transmission 12, 13, 17, 19
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 1

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Data Link Connector - Engine
(Diesel)BK Near T/O for Water In Fuel Sensor N/S
Dome Lamp BK Center of Headliner N/S
Door Ajar Switch-Driver (Base) BK Left Front Door 41
Door Ajar Switch-Left Rear (Base) BK Left Rear Door 43
Door Ajar Switch-Right Rear (Base) BK Right Rear Door 43
Door Lock Motor/Ajar Switch-Driver
(Except Base)BK Left Front Door 41
Door Lock Motor/Ajar Switch-Left
Rear (Except Base)BK Left Rear Door 43
Door Lock Motor/Ajar Switch-
PassengerBK Right Front Door 42
Door Lock Motor/Ajar Switch-Right
Rear (Except Base)BK Right Rear Door 43
Door Lock Switch-Passenger BL In Right Front Door 42
Driver Airbag Squib BK In Steering Column N/S
Driver Blend Door Actuator (Dual
Zone)BK Right Side of HVAC N/S
Driver Door Module C1 BL In Left Front Door 41
Driver Door Module C2 BL In Left Front Door 41
EGR Solenoid Right Front Engine 9
Electric Brake Provision Rear of Engine 22, 24
Engine Control Module C1 BK Left Engine 10
Engine Control Module C2 BK Left Engine 10
Engine Coolant Temperature
SensorBK Near Generator 6
Engine Oil Pressure Switch BK Lower Left Side of Engine 6, 9
Evap/Purge Solenoid BK Left Fender Side Shield 23, 25
Evaporator Temperature Sensor BK Right Side of HVAC N/S
Fog Lamp-Left WT Left Front Facia N/S
Fog Lamp-Right WT Right Front Facia N/S
Fuel Control Actuator (Diesel) BK Left Rear Engine N/S
Fuel Heater (Diesel) BK Left Side Engine 10
Fuel Injector No. 1 BK At Fuel Injector 6
Fuel Injector No. 2 BK At Fuel Injector 3
Fuel Injector No. 3 BK At Fuel Injector 6
Fuel Injector No. 4 BK At Fuel Injector 3
Fuel Injector No. 5 BK At Fuel Injector 6
Fuel Injector No. 6 BK At Fuel Injector 3
Fuel Injector No. 7 BK At Fuel Injector 6
Fuel Injector No. 8 BK At Fuel Injector 3
Fuel Pump Module LT GY At Fuel Tank 50
Fuel Pump Motor (Diesel) BK Left Side Engine 10
Generator BK Front of Engine 6, 9, 10
8W - 91 - 4 8W-91 CONNECTOR/GROUND/SPLICE LOCATIONDR
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
Glove Box Lamp and Switch BK At Glove Box 35, 39
Governor Pressure Sensor BK Left Rear of Transmission N/S
Hands Free Module Right Instrument Panel 39
Headlamp Switch BK Left Side of Instrument Panel 32, 35, 38
Headlamp-Left BL At Headlamp 23, 28, 29
Headlamp-Right BL At Headlamp 1, 21, 26
Heated Seat Cushion - Driver BL Under Driver Seat N/S
Heated Seat Cushion - Passenger BL Under Passenger Seat N/S
Heated Seat Switch-Driver RD Center of Instrument Panel 33, 35, 36
Heated Seat Switch-Passenger BL Center of Instrument Panel 33, 35, 36
Horn Switch WT In Steering Wheel N/S
Horn-High Note BK Left Front Fender 23, 28, 29
Horn-Low Note BK Left Front Fender 23, 29
Idle Air Control Motor BK On Throttle Body 6
Ignition Coil GY Left Rear of Engine N/S
Ignition Switch BK Steering Column 31
Inlet Air Temperature/Pressure
SensorBK Right Side Engine 10
Input Speed Sensor BK At Transmission 15, 16
Instrument Cluster C1 GY Rear of Instrument Cluster 35
Instrument Cluster C2 GY Rear of Instrument Cluster 35
Instrument Cluster C3 WT Rear of Instrument Cluster 35
Intake Air Heater Relay Right Engine Compartment 2
Intake Air Temperature/Manifold
Absolute Pressure Sensor (Diesel)BK Left rear Engine N/S
Intake Air Temperature Sensor BK On Intake Manifold 5
Integrated Power Module C1 BK Left Front Fender 26, 28
Integrated Power Module C2 WT Left Front Fender 26, 28
Integrated Power Module C3 GR Left Front Fender 26, 28
Integrated Power Module C4 WT Left Front Fender 26, 28
Integrated Power Module C5 BK Left Front Fender 26, 28
Integrated Power Module C6 BK Left Front Fender 25, 26, 28
Integrated Power Module C7 GY Left Front Fender 26, 28
Integrated Power Module FCM BK In IPM N/S
Knock Sensor BK Left Rear of Engine 5, 7, 9
License Lamp-Left BK At Rear Bumper 50, 51
License Lamp-Right BK At Rear Bumper 50, 51
Lift Pump Motor BK Near T/O for WIF Sensor N/S
Line Pressure Sensor BK Right Rear of Transmission 15, 18
Lumbar Motor-Driver DK GY At Driver Seat N/S
Lumbar Motor-Passenger BK At Passenger Seat N/S
Manifold Absolute Pressure Sensor GY Left Front of Intake Manifold 6
Mode Door Actuator 1 BK Right Side of HVAC N/S
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 5
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

CONNECTOR NAME/NUMBER COLOR LOCATION FIG.
PTO Switch Near G107 N/S
Radio C1 (Base) GY Rear of Radio 35, 36
Radio C1 (Premium) BK Rear of Radio 36
Radio C2 (Premium) BK Rear of Radio 36
Radio Antenna - At Antenna Base 37
Radio Antenna Cable - Right Kick Panel 36, 37
Recirculation Door Actuator BK Right Side of HVAC N/S
Red Brake Warning Indicator
SwitchBK Near Master Cylinder 22, 25, 29
Remote Radio Switch-Left BK At Steering Wheel N/S
Remote Radio Switch-Right BK At Steering Wheel N/S
Seat Belt Pretensioner-Left YL Left B-Pillar 44, 46
Seat Belt Pretensioner-Right YL Right B-Pillar 45, 47
Seat Belt Switch-Driver DK GY Left B-Pillar N/S
Seat Belt Tension Reducer
(Standard Cab)YL Left B-Pillar 44
Seat Heater Interface Module GN Under Driver Seat N/S
Sentry Key Immobilizer Module BK On Steering Column 30
Side Marker - Left Front (Dual
Wheels)BK Front of Left Rear Fender 52
Side Marker - Left Rear (Dual
Wheels)BK Rear of Left Rear Fender 52
Side Marker - Right Front (Dual
Wheels)BK Front of Right Rear Fender 52
Side Marker - Right Rear (Dual
Wheels)BK Rear of Right Rear Fender 52
Speaker-Center Instrument Panel WT Center of Instrument Panel 35, 36
Speaker-Left Front Door WT In Left Front Door 41
Speaker-Left Instrument Panel BK Left Side of Instrument Panel 35, 38
Speaker-Left Rear (Standard Cab) WT In Lower Left B-Pillar 44
Speaker-Left Rear Door (Quad
Cab)WT In Left Rear Door 43
Speaker-Right Front Door WT In Right Front Door 42
Speaker-Right Instrument Panel BK Right Side of Instrument Panel 35, 39
Speaker-Right Rear (Standard
Cab)BK In Lower Right B-Pillar 45
Speaker-Right Rear Door (Quad
Cab)BK In Right Rear Door 43
Speed Control Servo BK Left Front Side of Engine
Compartment23, 25
Speed Control Switch - Left
(Except ETC)GN Steering Wheel N/S
Speed Control Switch - Right
(Except ETC)GN Steering Wheel N/S
Speed Control Switch-Left (ETC) WT At Steering Wheel N/S
DR8W-91 CONNECTOR/GROUND/SPLICE LOCATION 8W - 91 - 7
CONNECTOR/GROUND/SPLICE LOCATION (Continued)

of oil and coolant. Can be used on threaded and
machined parts under all temperatures. This mate-
rial is used on engines with multi-layer steel (MLS)
cylinder head gaskets. This material also will pre-
vent corrosion. MopartGasket Sealant is available in
a 13 oz. aerosol can or 4oz./16 oz. can w/applicator.
FORM-IN-PLACE GASKET AND SEALER
APPLICATION
Assembling parts using a form-in-place gasket
requires care but it's easier than using precut gas-
kets.
MopartGasket Maker material should be applied
sparingly 1 mm (0.040 in.) diameter or less of sealant
to one gasket surface. Be certain the material sur-
rounds each mounting hole. Excess material can eas-
ily be wiped off. Components should be torqued in
place within 15 minutes. The use of a locating dowel
is recommended during assembly to prevent smear-
ing material off the location.
MopartEngine RTV GEN II or ATF RTV gasket
material should be applied in a continuous bead
approximately 3 mm (0.120 in.) in diameter. All
mounting holes must be circled. For corner sealing, a
3.17 or 6.35 mm (1/8 or 1/4 in.) drop is placed in the
center of the gasket contact area. Uncured sealant
may be removed with a shop towel. Components
should be torqued in place while the sealant is still
wet to the touch (within 10 minutes). The usage of a
locating dowel is recommended during assembly to
prevent smearing material off the location.
MopartGasket Sealant in an aerosol can should be
applied using a thin, even coat sprayed completely
over both surfaces to be joined, and both sides of a
gasket. Then proceed with assembly. Material in a
can w/applicator can be brushed on evenly over the
sealing surfaces. Material in an aerosol can should be
used on engines with multi-layer steel gaskets.
STANDARD PROCEDURE - ENGINE GASKET
SURFACE PREPARATION
To ensure engine gasket sealing, proper surface
preparation must be performed, especially with the
use of aluminum engine components and multi-layer
steel cylinder head gaskets.
Neveruse the following to clean gasket surfaces:
²Metal scraper
²Abrasive pad or paper to clean cylinder block
and head
²High speed power tool with an abrasive pad or a
wire brush (Fig. 2)
NOTE: Multi-Layer Steel (MLS) head gaskets require
a scratch free sealing surface.
Only use the following for cleaning gasket surfaces:²Solvent or a commercially available gasket
remover
²Plastic or wood scraper (Fig. 2)
²Drill motor with 3M RolocŸ Bristle Disc (white
or yellow) (Fig. 2)
CAUTION: Excessive pressure or high RPM (beyond
the recommended speed), can damage the sealing
surfaces. The mild (white, 120 grit) bristle disc is
recommended. If necessary, the medium (yellow, 80
grit) bristle disc may be used on cast iron surfaces
with care.
REMOVAL
(1) Disconnect the battery negative cable.
(2) Remove hood. Mark hood hinge location for
reinstallation.
(3) Remove air cleaner assembly.
(4) Remove radiator core support bracket.
(5) Remove fan shroud with viscous fan assembly.
(6) Remove drive belt.
(7) Remove A/C compressor and secure away from
engine.
(8) Remove generator and secure away from
engine.
NOTE: Do NOT remove the phenolic pulley from the
P/S pump. It is not required for P/S pump removal.
(9) Remove power steering pump with lines
attached and secure away from engine.
(10) Drain cooling system.
(11) Disconnect the heater hoses from the engine.
Fig. 2 Proper Tool Usage For Surface Preparation
1 - ABRASIVE PAD
2 - 3M ROLOCŸ BRISTLE DISC
3 - PLASTIC/WOOD SCRAPER
9 - 10 ENGINE - 3.7LDR
ENGINE - 3.7L (Continued)