Starting System: Diagnosis Dodge Pickup R2500

BASIC INSPECTION

For complete starter wiring circuit diagrams, WIRING DIAGRAMS , Before removing any unit from starting system for repair or diagnosis, perform the following inspections

1. Battery - Visually inspect battery for indications of physical damage and loose or corroded cable connections. Determine state-of-charge and cranking capacity of battery. Charge or replace battery if required. NOTE: If equipped with diesel engine, a dual battery system may be used, and both batteries must be inspected.
2. Ignition Switch - Visually inspect ignition switch for indications of physical damage and loose or corroded wire harness connections. See appropriate IGNITION SYSTEMS article.
3. Clutch Pedal Position Switch - If equipped with manual transmission, visually inspect clutch pedal position switch for indications of physical damaged and loose or corroded wire harness connections. See appropriate TRANSMISSIONS article under CLUTCHES.
4. Park/Neutral Position Switch - If equipped with automatic transmission, visually inspect park/neutral position switch for indications of physical damage and loose or corroded wire harness connections. See appropriate TRANSMISSIONS article.
5. Starter Relay - Visually inspect starter relay for indications of physical damage and loose or corroded wire harness connections.
6. Starter Motor - Visually inspect starter motor for indications of physical damage and loose or corroded wire harness connections.
7. Starter Solenoid - Visually inspect starter solenoid for indications of physical damage and loose or corroded wire harness connections.
8. Wiring - Visually inspect wire harnesses for damage. Repair or replace any faulty wiring, as required. See «WIRING DIAGRAMS»(ref-164936-S35990875752004081800000) .

COLD CRANKING TEST

For complete starter wiring circuit diagrams, see WIRING DIAGRAMS . The battery must be fully-charged and load-tested before proceeding.

Scheme 1

1. Connect volt-ampere tester to battery terminals. (Scheme 1) See instructions provided by manufacturer of volt-ampere tester being used. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, tester should be connected to battery on left side of vehicle only. Also, tester current reading must be taken from positive battery cable lead that connects to starter motor.
2. Fully engage parking brake.
3. If equipped with manual transmission, place gearshift selector lever in Neutral position and block clutch pedal in fully depressed position. If equipped with automatic transmission, place gearshift selector lever in Park position.
4. Verify that all lamps and accessories are turned off.
5. To prevent a gasoline engine from starting, remove Automatic Shut Down (ASD) relay. To prevent a diesel engine from starting, remove Fuel Pump Relay. These relays are located in Power Distribution Center (PDC). Refer to label on PDC cover for relay location. WARNING: If equipped with diesel engine, attempt to start engine a few times before proceeding with following step.
6. Rotate and hold ignition switch in Start position. Note cranking voltage and current (amperage) draw readings shown on volt-ampere tester. If voltage reads below 9.6 volts, see «STARTER MOTOR»(ref-164936-S28209061332004082000000) under COMPONENT TESTING. If starter motor is not OK, replace faulty starter motor. If voltage reads above 9.6 volts and current (amperage) draw reads below specifications, see «FEED CIRCUIT TEST»(ref-164936-S09013243552004081900000). If voltage reads 12.5 volts or greater and starter motor does not turn, see «CONTROL CIRCUIT TESTING»(ref-164936-S31843306362004081900000). If voltage reads 12.5 volts or greater and starter motor turns very slowly, see «FEED CIRCUIT TEST»(ref-164936-S09013243552004081900000).

Note. A cold engine will increase starter current (amperage) draw reading, and reduce battery voltage reading.

FEED CIRCUIT TEST

The starter feed circuit test (voltage drop method will determine if there is excessive resistance in high-amperage feed circuit. For complete starter wiring circuit diagrams, see WIRING DIAGRAMS .

When performing these tests, it is important to remember that voltage drop is giving an indication of resistance between two points at which voltmeter probes are attached.

Example: When testing resistance of positive battery cable, touch voltmeter leads to positive battery cable clamp and cable connector at starter solenoid. If you probe positive battery terminal post and cable connector at starter solenoid, you are reading combined voltage drop in positive battery cable clamp-to-terminal post connection and positive battery cable.

The following operation will require a voltmeter accurate to 1/10 (0.10) volt. Before performing tests, be certain that following procedures are accomplished

1. Battery is fully-charged and load-tested.
2. Fully engage parking brake.
3. If equipped with manual transmission, place gearshift selector lever in Neutral position and block clutch pedal is fully depressed position. If equipped with automatic transmission, place gearshift selector lever in Park position.
4. Verify that all lamps and accessories are turned off.
5. To prevent a gasoline engine from starting, remove Automatic Shut Down (ASD) relay. To prevent a diesel engine from starting, remove Fuel Pump Relay. These relays are located in Power Distribution Center (PDC). Refer to label on PDC cover for relay location.

Scheme 2

Scheme 3

Scheme 4

Scheme 5

Scheme 6

1. Connect positive lead of voltmeter to negative battery cable terminal post. Connect negative lead of voltmeter to negative battery cable clamp. (Scheme 2) Rotate and hold ignition switch in Start position. Observe voltmeter. Of voltage is detected, correct poor contact between cable clamp and terminal post. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, procedure must be performed twice, once for each battery.
2. Connect positive lead of voltmeter to positive battery terminal post. Connect negative lead of voltmeter to battery positive cable clamp. (Scheme 3) Rotate and hold ignition switch in Start position. Observe voltmeter. If voltage is detected, correct poor contact between cable clamp and terminal post. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, this procedure must be performed twice, once for each battery.
3. Connect voltmeter to measure between battery positive terminal post and starter solenoid battery terminal stud. (Scheme 4) Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten battery cable connection at solenoid. Repeat test. If reading is still above 0.2 volt, replace faulty positive battery cable. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, this procedure must be performed on driver side battery only.
4. Connect voltmeter to measure between negative battery terminal post and a good clean ground on engine block. (Scheme 5) Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten negative battery cable attachment on engine block. Repeat test. If reading is still above 0.2 volt, replace faulty negative battery cable. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, this procedure must be performed twice, once for each battery.
5. Connect positive lead of voltmeter to starter housing. Connect negative lead of voltmeter to negative battery terminal post. (Scheme 6) Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, correct poor starter to engine block ground contact. NOTE: Certain diesel equipped models use dual batteries. If equipped with dual battery system, this procedure must be performed on driver side battery only.
6. If equipped with dual battery system (certain diesel equipped models), connect positive lead of voltmeter to positive battery cable clamp on battery located on left side of vehicle. Connect negative lead of voltmeter to positive battery terminal post on battery located on right side of vehicle. Rotate and hold ignition switch in Start position. Observe voltmeter. If reading is above 0.2 volt, clean and tighten battery cables at both batteries. Repeat test. If reading is still above 0.2 volt, replace faulty positive battery cable.

If resistance tests detect no feed circuit problems, see STARTER MOTOR under COMPONENT TESTING.

CONTROL CIRCUIT TESTING

The starter control circuit components should be tested in the order in which they are listed, as follows

1. Starter Relay - See «STARTER RELAY»(ref-164936-S06671937652004082000000) under COMPONENT TESTING.
2. Starter Solenoid - See «STARTER MOTOR»(ref-164936-S28209061332004082000000) under COMPONENT TESTING.
3. Ignition Switch - See appropriate STEERING COLUMN SWITCHES article in ACCESSORIES & EQUIPMENT.
4. Clutch Pedal Position Switch - See appropriate article in CLUTCHES.
5. Park/Neutral Position Switch - See appropriate TRANSMISSIONS article.
6. Wire harnesses and connections - See «WIRING DIAGRAMS»(ref-164936-S35990875752004081800000) .

RELAY CIRCUIT TEST

1. The relay common feed terminal cavity (30) is connected to battery voltage and should be hot at all times. If OK, go to next step. If not OK, repair open circuit to fuse in PDC as required.
2. The relay normally closed terminal (87A) is connected to terminal 30 in the de-energized position, but is not used for this application. Go to next step.
3. The relay normally open terminal (87) is connected to common feed terminal (30) in the energized position. This terminal supplies battery voltage to starter solenoid field coils. There should be continuity between cavity for relay terminal 87 and starter solenoid terminal at all times. If OK, go to next step. If not OK, repair open circuit to starter solenoid as required.
4. The coil battery terminal (86) is connected to electromagnet in relay. It is energized when ignition switch is held in Start position. On vehicles with manual transmission, clutch pedal must be fully depressed for this test. Check for battery voltage at cavity for relay terminal 86 with ignition switch in Start position, and no voltage when ignition switch is released to On position. If OK, go to next step. If not OK with automatic transmission, check for open or short circuit to ignition switch and repair, if required. If circuit to ignition switch is OK, see appropriate article on IGNITIONS. If not OK with a manual transmission, check circuit between relay and clutch pedal position switch for open or a short. If circuit is OK, see appropriate article on CLUTCHES.
5. The coil ground terminal (85) is connected to the electromagnet in the relay. On vehicles with manual transmission, it is grounded at all times. On vehicles with automatic transmission, it is grounded through park/neutral position switch only when gearshift selector lever is in Park or Neutral positions. Check for continuity to ground at cavity for relay terminal 85. If not OK with manual transmission, repair circuit to ground as required. If not OK with automatic transmission, check for pen or short circuit to park/neutral position switch and repair, if required.

Scheme 7

1. Disconnect and isolate negative battery cable.
2. Raise and support vehicle.
3. Note: If equipped with 4WD and certain transmissions, a support bracket is used between front axle and side of transmission. Remove 2 support bracket bolts at transmission. Pry support bracket slightly to gain access to lower starter mounting bolt.
4. Remove 1 bolt and 1 nut if equipped with a manual transmission. (Scheme 7)
5. Remove 2 bolts if equipped with an automatic transmission. (Scheme 8)
6. Move starter motor towards front of vehicle far enough for nose of starter pinion housing to clear housing. Always support starter motor during this process, do not let starter motor hang from wire harness.
7. Tilt nose downwards and lower starter motor far enough to access and remove nut that secures battery positive cable wire harness connector eyelet to solenoid battery terminal stud. Do not let starter motor hang from wire harness.
8. Remove battery positive cable wire harness connector eyelet from solenoid battery terminal stud.
9. Disconnect battery positive cable wire harness connector from solenoid terminal connector receptacle.
10. Remove starter motor.

Scheme 8