1999 DODGE RAM wiring

FUEL DELIVERY
Fuel Filter/Water Separator
1) A restricted fuel filter/water separator may cause engine
starting problems, prevent engine from accelerating, low power or
White exhaust smoke.
2) When ignition is first turned on, WATER-IN-FUEL (WIF)
warning light should come on for 2 seconds to perform bulb and wiring
circuit test and then go off. WATER-IN-FUEL (WIF) warning light is
located on instrument panel, just below tachometer.
3) If WATER-IN-FUEL (WIF) warning light stays on, water
should be drained from fuel filter/water separator. To drain water
from fuel filter/water separator, ensure engine is not running. Place
drain pan below drain tube at fuel filter/water separator.
4) Rotate handle on drain valve forward, toward front of
vehicle to DRAIN position. Drain valve is located near top of fuel
filter/water separator.
5) If no water exists and a clean flow of diesel fuel exists,
rotate handle on drain valve back to CLOSE position. Go to next step.
If water exists, allow water to drain until clean flow of diesel fuel
exists. Rotate handle on drain valve back to CLOSE position. Go to
next step.
6) Verify fuel filter/water separator has been serviced
according to proper service schedule. See SERVICE & ADJUSTMENT
SPECIFICATIONS - TRUCKS article. Ensure pre-filter was cleaned when
fuel filter/water separator was serviced. Pre-filter is located at
bottom of fuel heater on driver's side of engine. No other testing
information is available from manufacturer.
Fuel Heater
1) Malfunctioning fuel heater may cause excessive wax build-
up in fuel filter/water separator during cold ambient temperatures.
Wax build-up may cause hard starting, prevent engine from
accelerating, low power, or Blue or White smoke.
2) Disconnect electrical connector at fuel heater. Fuel
heater is located in top of fuel filter housing. Using ohmmeter, check
resistance between electrical terminals on fuel heater.
3) Resistance should be about one ohm when fuel is cold, and
about 1000 ohms when fuel is warm. Replace fuel heater if resistance
is not within specification.
NOTE: Fuel heater receives battery voltage from fuel heater relay.
Fuel heater relay is located in Power Distribution Center
(PDC), next to left battery. Refer to PDC lid for relay
location. For testing of fuel heater relay, see RELAYS under
RELAYS & SOLENOIDS. Consult wiring diagram for wiring circuit
testing. See appropriate wiring diagram in WIRING DIAGRAMS
article.
Fuel Transfer Pump Preliminary Inspection
1) Check for restricted or leaking fuel supply line to fuel
transfer pump or fuel return line located on driver's side of engine.
Repair fuel supply line or fuel return line if restricted or leaking.
2) Check for fuel leaking from weep hole on housing of fuel
transfer pump. Replace fuel transfer pump if fuel is leaking from weep
hole. Check fuel transfer pump for output pressure, pressure drop,
supply restriction, and air leaks.
NOTE: Separate pressure tests are necessary because transfer pump
operates at 2 pressure cycles, depending on whether engine is
running or cranking.

NOTE: A leaking fuel injector or high-pressure fuel line may cause
a rough idle, Black smoke, poor engine performance, poor fuel
economy and fuel knock. Following procedure is for
determining if fuel injector is defective.
WARNING: DO NOT allow diesel fuel to contact hot engine when checking
fuel injector, as high exhaust temperatures could cause a
fire. Use care when working around high-pressure fuel lines,
as fuel is under extreme pressure and could penetrate skin,
causing personal injury. Wear safety goggles and protective
clothing when checking fuel injectors.
Fuel Injector
1) Since a leaking high-pressure fuel line may cause the same
symptoms, check for leaking high-pressure fuel line before checking
fuel injector. To check for a leaking high-pressure fuel line, start
engine and allow engine to idle.
2) Inspect high-pressure fuel lines and connections for signs
of fuel leakage by placing cardboard over high-pressure fuel line and
connection. Note if leak is being detected by fuel being sprayed onto
cardboard. If leak exists, repair leak by tightening high-pressure
fuel line nut to 18 ft. lbs. (24 N.m) or replacing high-pressure fuel
line as necessary. If high-pressure fuel line is replaced, bleed air
from fuel system. See FUEL LINE BLEEDING under FUEL SYSTEM in REMOVAL,
OVERHAUL & INSTALLATION article.
3) To check for defective fuel injector, start and idle
engine. Loosen high-pressure fuel line nut at fuel injector and listen
for a decrease in engine speed. Tighten high-pressure fuel line nut to
18 ft. lbs. (24 N.m).
4) If fuel injector is operating properly, engine idle speed
should decrease when high-pressure fuel line nut is loosened. Repeat
procedure on each fuel injector.
5) If engine idle speed does not decrease, fuel injector is
defective and should be removed and tested with a diesel fuel injector
tester. Replace fuel injector if fuel injector opening (pop) pressure
is not about 4500 psi (316 kg/cm

).
EMISSION SYSTEMS & SUB-SYSTEMS
INTAKE MANIFOLD AIR HEATER SYSTEM
Intake Manifold Air Heater Preheat/Postheat Cycle
For testing information on intake manifold air heater system,
see DTC P0380: INTAKE AIR HEATER RELAY NO. 1 CONTROL CIRCUIT and DTC
P0382: INTAKE AIR HEATER RELAY NO. 2 CONTROL CIRCUIT tests in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
MISCELLANEOUS CONTROLS
NOTE: Although some controlled devices listed here are not
technically engine performance components, they can affect
driveability if they malfunction.
TRANSMISSION
Park/Neutral Switch (A/T Models)
Park/neutral switch is mounted on transmission case, near
shift lever and contains a 3-pin connector. If problem exists in
park/neutral switch or wiring circuit, a Diagnostic Trouble Code (DTC)\
will be stored in Powertrain Control Module (PCM). See DTC P1899: P/N
SWITCH STUCK IN PARK OR IN GEAR test in SELF-DIAGNOSTICS - JEEP,

TRUCKS & RWD VANS article.
Transmission Governor Pressure Sensor (A/T Models)
Transmission governor pressure sensor is located on
transmission valve body. If problem exists in transmission governor
pressure sensor or wiring circuit, a Diagnostic Trouble Code (DTC)
will be stored in Powertrain Control Module (PCM). See appropriate
governor pressure sensor test in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD
VANS article.
Transmission Overdrive Solenoid (A/T Models)
Transmission overdrive solenoid may also be referred to as
overdrive solenoid or 3-4 solenoid. Transmission overdrive solenoid is
located transmission valve body. If problem exists in transmission
overdrive solenoid or wiring circuit, a Diagnostic Trouble Code (DTC)
will be stored in Powertrain Control Module (PCM). See DTC P1740: TCC
OR O/D SOLENOID PERFORMANCE test in SELF-DIAGNOSTICS - JEEP, TRUCKS &
RWD VANS article.
Transmission Relay (A/T Models)
See RELAYS under RELAYS & SOLENOIDS.
Transmission Speed Sensor (A/T Models)
Transmission speed sensor may also be referred to as
transmission output shaft speed sensor. Transmission speed sensor is
located on overdrive case at rear of transmission. Transmission speed
sensor contains a 2-pin connector with a Dark Blue/Black wire and a
Light Green/Black wire. If problem exists in transmission speed sensor
or wiring circuit, a Diagnostic Trouble Code (DTC) will be stored in
Powertrain Control Module (PCM). See DTC P0720: LOW OUTPUT SPEED
SENSOR RPM, ABOVE 15 MPH test in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD
VANS article.
Transmission Temperature Sensor (A/T Models)
Transmission temperature sensor is incorporated into governor
pressure sensor on transmission valve body. If problem exists in
transmission temperature sensor or wiring circuit, a Diagnostic
Trouble Code (DTC) will be stored in Powertrain Control Module (PCM)\
.
See appropriate transmission temperature sensor test in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
Transmission Torque Converter Clutch Solenoid (A/T Models)
The transmission Torque Converter Clutch (TCC) solenoid is
located on transmission valve body. If problem exists in TCC solenoid
or wiring circuit, a Diagnostic Trouble Code (DTC) will be stored in
Powertrain Control Module (PCM). See DTC P0743: TORQUE CONVERTER
CLUTCH SOLENOID/TRANSMISSION RELAY CIRCUIT test in SELF-DIAGNOSTICS -
JEEP, TRUCKS & RWD VANS article.


I - S YSTE M /C O M PO NEN T T E STS - R W D - G ASO LIN E

1999 D odge P ic ku p R 1500
1999 ENGINE PERFORMANCE
CHRY - System & Component Testing - Trucks & RWD Vans - Gas
Dodge: Dakota, Durango, Ram Pickup, Ram Van, Ram Wagon
Jeep Cherokee, Grand Cherokee, Wrangler
INTRODUCTION
Before testing individual components or systems, perform
procedures in BASIC DIAGNOSTIC PROCEDURES - TRUCKS & RWD VANS -
GASOLINE article. Since many computer controlled and monitored
components set a fault message if they malfunction, also perform
procedures in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
NOTE: Testing of individual components does not isolate possible
shorts or opens in wiring harness of electronically
controlled systems. Perform all voltage tests using a Digital
Volt-Ohmmeter (DVOM) with a minimum 10-megohm input impedance\
unless otherwise instructed in procedure. Use an ohmmeter to
isolate wiring harness shorts or opens.
COMPUTERIZED ENGINE CONTROLS
POWERTRAIN CONTROL MODULE (PCM)
PCM power and ground circuits may be checked by performing
TEST NS-1 in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article. For
PCM location, see PCM LOCATION table.
PCM LOCATION









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Application Location
Dakota & Durango ................. Right Front Fender, Near Firewall
Ram Pickup, Ram Van & Ram Wagon ...... On Firewall, Near Wiper Motor









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ENGINE SENSORS, SOLENOIDS & SWITCHES
SENSORS
Camshaft Position (CMP) Sensor
See appropriate DTC P0340: NO CAM SIGNAL AT PCM test in SELF-
DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
Crankshaft Position (CKP) Sensor
See appropriate DTC P0320: NO CRANK REFERENCE SIGNAL AT PCM
test in SELF-DIAGNOSTICS - JEEP, TRUCKS & RWD VANS article.
Engine Coolant Temperature (ECT) Sensor
See appropriate DTC P0117: ECT SENSOR VOLTAGE TOO LOW and DTC
P0118: ECT SENSOR VOLTAGE TOO HIGH tests in SELF-DIAGNOSTICS - JEEP,
TRUCKS & RWD VANS article.
Heated Oxygen Sensor (HO2S)
See appropriate DTC for oxygen sensor in SELF-DIAGNOSTICS -
JEEP, TRUCKS & RWD VANS article.

SYSTE M W IR IN G D IA G RAM S

1999 D odge P ic ku p R 1500
1999 System Wiring Diagrams
Dodge - Pickup R1500
AIR CONDITIONING
Heater Circuit

* Air in fuel system:
* Coolant leak into combustion chamber:
* Block heater malfunction in cold weather:
* Clogged or defective fuel filter:
* Poor fuel quality:
* Fuel injector malfunctioning or loose:
* Restricted or blocked fuel injection or supply lines:
* Intake/exhaust valves not adjusted properly (tight):
* Intake heaters malfunctioning:
* Internal engine damage.
BLUE EXHAUST SMOKE
* Air filter dirty or plugged:
* Air intake system restricted:
* Air leak in intake between turbocharger and intake
manifold:
* Restricted exhaust:
* Restricted turbocharger drain tube:
* Crankcase ventilation plugged:
* Valve stems, guides or seals worn or defective:
* Piston rings improperly gapped, worn or broken:
* Internal engine wear:
* Turbocharger failure.
INTERMITTENTS
INTERMITTENT PROBLEM DIAGNOSIS
Intermittent fault testing requires duplicating circuit or
component failure to identify problem. These procedures may lead to
PCM setting a Diagnostic Trouble Code (FTC) which may help in
diagnosis.
If problem vehicle does not produce DTCs, monitor voltage or
resistance values using a Digital Volt-Ohmmeter (DVOM) while
attempting to reproduce conditions causing intermittent fault. A
status change on DVOM indicates a fault has been located.
Use a DVOM to pinpoint faults. When monitoring voltage,
ensure ignition switch is in ON position or engine is running. Ensure
ignition switch is in OFF position or negative battery cable is
disconnected when monitoring circuit resistance. Status changes on
DVOM during test procedures indicate area of fault.
TEST PROCEDURES
Intermittent Simulation
To reproduce conditions creating an intermittent fault, use
following methods:
* Lightly vibrate component
* Heat component
* Wiggle or bend wiring harness
* Spray component with water
* Remove/apply vacuum source
Monitor circuit/component voltage or resistance while
simulating intermittent. If engine is running, monitor for diagnostic
trouble codes. Use test results to identify a faulty component or
circuit.

* Lightly vibrate component
* Heat component
* Wiggle or bend wiring harness
* Spray component with water
* Remove/apply vacuum source.
Monitor circuit/component voltage or resistance while
simulating intermittent. If engine is running, monitor for DTCs. Use
test results to identify a faulty component or circuit.

Fig. 6: Locating Intake Manifold Air Heater Relays
Courtesy of Chrysler Corp.
Malfunction Indicator Light (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
Oil Pressure Gauge/Warning Light
Oil pressure gauge/warning light output from Engine Control
Module (ECM) to instrument cluster is routed on CCD Bus circuit.