Charging System Check 21-SI
Tools Required
| • | J 39200 Digital Multimeter |
| • | J 35590 Inductive Current Clamp |
Using the Digital Multimeter:
- Disconnect the negative battery cable. Refer to Battery Cable Replacement .
- Connect an ammeter in series between the BAT terminal of the generator and the output lead.
- Connect the negative battery cable. Refer to Battery Cable Replacement .
- Start the engine.
- Turn ON the following components:
- Connect a carbon pile across the battery.
- Operate the engine at 2500 RPM.
- Adjust the carbon pile as necessary in order to obtain the maximum current output.
- If the ampere output is within 10 amperes of the rated output stamped on the generator frame, the generator functions properly.
- If the ampere output is not within 10 amperes of the rated output stamped on the generator frame, repair the generator. Refer to Generator Overhaul
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
| • | The radio |
| • | The windshield wipers |
| • | The headlamps (high beam) |
| • | The blower motor (high speed) |
Important: Residual magnetism in the rotor causes the initial voltage buildup. Increase the engine speed as necessary in order to obtain the maximum current output.
Using the Inductive Current Clamp:
- Install the J 35590 .
- Start the engine.
- Turn ON the following components:
- Connect a carbon pile across the battery.
- Operate the engine at 2500 RPM.
- Adjust the carbon pile as necessary in order to obtain the maximum current output.
- If the ampere output is within 10 amperes of the rated output stamped on the generator frame, the generator functions properly.
- If the ampere output is not within 10 amperes of the rated output stamped on the generator frame, repair the generator. Refer to Generator Overhaul .
| • | The radio |
| • | The windshield wipers |
| • | The headlamps (high beam) |
| • | The blower motor (high speed) |
Important: Residual magnetism in the rotor causes the initial voltage buildup. Increase the engine speed as necessary in order to obtain the maximum current output.
Charging System Check SCT
Step | Action | Normal Result(s) | Abnormal Result(s)* | ||||||
|---|---|---|---|---|---|---|---|---|---|
1 | Move the ignition switch from the OFF position to the RUN position. | Battery indicator lamp turns ON, voltmeter gage reads between 12-14 volts. | Refer to:
| ||||||
2 | Move the Ignition Switch to the START position and then release. | The engine starts, the voltage gage reads between 13-16 volts, the battery indicator lamp turns OFF. | Refer to: | ||||||
3 | Run the engine at idle while observing the voltmeter gage and the battery indicator lamp. | Voltmeter gage holds steady between 13-16 volts and the battery indicator lamp is OFF. | Refer to Charging System Check . | ||||||
4 |
| Voltmeter gage holds steady between 13-16 volts and the battery indicator lamp is OFF. | Refer to Charging System Check . | ||||||
* Refer to the appropriate symptom diagnostic table for the applicable abnormal result. | |||||||||
Charging System Check Battery Test
Diagnostic Aids
Caution: Refer to Battery Disconnect Caution in the Preface section.
Important: The battery test using the J 42000 Battery Tester requires correct connections to the battery terminals. A failure to obtain the correct connections during the test may result in a failed test on a good battery.
Adhere to the following instructions in order to avoid an incorrect diagnosis due to poor connections:
| • | When testing the vehicle with the battery cables still connected, rock the J 42000 clips back and forth on the terminal bolt in order to cut through any coating or oxidation that may be present on the bolt. |
| Even new bolts contain a protective coating that may insulate or cause a resistance in the test circuit. |
| • | If it is uncertain that correct connections can be made to the battery terminal bolts in the vehicle, perform the following steps: |
| 1. | Disconnect the negative battery cable. |
| 2. | Disconnect the positive battery cable. |
| 3. | Install the test adapters on the terminals. |
| 4. | Follow the instructions for testing the battery outside of the vehicle. |
| • | If a REPLACE BATTERY result is obtained for a battery that is below 4°C (40°F), perform the following steps: |
| 1. | Disconnect the negative battery cable. |
| 2. | Disconnect the positive battery cable. |
| 3. | Allow the battery to sit in a warm place (above 15°C (60°F) for 6 hours. |
| 4. | Install the approved adapters. |
| 5. | Follow the instructions for testing the battery outside of the vehicle. |
| 6. | Replace the battery only if the second test shows a REPLACE BATTERY result. |
For warranty purposes, use the test code from the second test.
| • | If a REPLACE BATTERY result is obtained for a battery tested in the vehicle with the battery cables connected, perform the following steps: |
| 1. | Disconnect the negative battery cable. |
| 2. | Disconnect the positive battery cable. |
| 3. | Install the approved adapters. |
| 4. | Follow the instructions for testing the battery outside of the vehicle. |
| 5. | Replace the battery only if the second test shows a REPLACE BATTERY result. |
For warranty purposes, use the test code from the second test.
| • | Use the approved terminal adapters. |
| Do not use any common bolts or a combination of bolts, nuts, and washers as adapters when testing the battery. |
| Use the test adapters that are provided with the J 42000 tester or GM P/N 12303040 terminal adapters. If the adapters that are provided with the J 42000 tester require replacement, only use adapters with the GM P/N 12303040. Any other adapter may not contact the correct areas of the battery terminal, causing a resistance that may result in an invalid battery test result. |
Important: For warranty purposes, always place the test code displayed by the tester on the repair order. The number is a unique identifier that describes the test data for a particular battery at a particular time.
While the test code may occasionally repeat when retesting the same battery, it is more likely that a different code will result each time the battery is tested.Step | Action | Value(s) | Yes | No | ||||||
|---|---|---|---|---|---|---|---|---|---|---|
1 | Inspect the battery for a cracked, broken, or damaged case, which may indicated by battery acid leakage. Is the battery OK? | -- | Go to Step 2 | Go to Step 19 | ||||||
2 | Compare the Cold Cranking Amperage (CCA) and Reserve Capacity (RC) of the battery to the original battery or Original Equipment (OE) specification. Refer to Battery Usage . Does the battery meet or exceed the specifications? | -- | Go to Step 3 | Go to Step 19 | ||||||
3 | Does the hydrometer display a yellow dot? | -- | Go to Step 4 | Go to Step 5 | ||||||
4 | Tap the hydrometer lightly on top with the handle of a small screwdriver to dislodge any air bubbles inside the battery. Does the hydrometer still display a yellow dot? | -- | Go to Step 19 | Go to Step 5 | ||||||
5 |
Does the negative connector rotate? | -- | Go to Step 6 | Go to Step 7 | ||||||
6 | Use a torque wrench in order to verify the torque to loosen the negative battery terminal bolt. Is the torque above the specified value? | 10 N·m | Go to Step 8 | Go to Step 7 | ||||||
7 |
Caution: Refer to Battery Disconnect Caution in the Preface section. Disconnect the negative battery cable. Is the cable disconnected? | -- | Go to Step 9 | -- | ||||||
8 |
Caution: Refer to Battery Disconnect Caution in the Preface section.
Is the repair complete? | -- | Go to Step 9 | -- | ||||||
9 | Rotate the positive battery cable connector clockwise with light finger pressure. Does the positive connector rotate? | -- | Go to Step 10 | Go to Step 11 | ||||||
10 | Use a torque wrench in order to verify the torque to loosen the positive battery terminal bolt. Is the torque above the specified value? | 10 N·m | Go to Step 12 | Go to Step 11 | ||||||
11 |
Caution: Refer to Battery Disconnect Caution in the Preface section. Disconnect the positive battery cable. Is the cable disconnected? | -- | Go to Step 13 | -- | ||||||
12 |
Caution: Refer to Battery Disconnect Caution in the Preface section.
Is the repair complete? | -- | Go to Step 13 | -- | ||||||
13 |
Are the metal connecting parts clean and in good condition? | -- | Go to Step 14 | -- | ||||||
14 |
Is the cable bolt properly tightened? | -- | Go to Step 15 | -- | ||||||
15 |
Is the cable bolt properly tightened? | -- | Go to Step 16 | -- | ||||||
16 |
Important: Make sure all electrical loads are turned OFF.
Did the tester pass the battery? | -- | Go to Step 17 | Go to Step 18 | ||||||
17 |
Did you complete this action? | -- | Battery OK | -- | ||||||
18 |
Did you complete the replacement? | -- | Battery OK | -- | ||||||
19 | Replace the battery. Refer to Battery Replacement . Did you complete the replacement? | -- | Battery OK | -- |
Charging System Check CS-144
Tools Required
| • | J 39200 Digital Multimeter |
| • | J 35590 Inductive Current Clamp |
- Disconnect the wire harness from the generator.
- Set the J 39200 to the DC voltage scale.
- Connect the J 39200 from ground to the L terminal in the wiring harness.
- Verify that the voltage is B+.
- Correct any faults as necessary.
- Connect the electrical connector to the generator.
- Turn OFF all of the accessories.
- Run the engine at 2500 RPM.
- Measure the voltage across the battery.
- Disconnect the negative battery cable. Refer to Battery Cable Replacement .
- If you use the J 39200 , connect an ammeter in series between the BAT terminal of the generator and the output lead. Ensure that the ammeter is able to measure 115 amps of current.
- If you use the J 35590 , install the J 35590 around the generator output lead.
- Connect the negative battery cable. Refer to Battery Cable Replacement .
- Connect a carbon pile across the battery.
- Start the engine.
- Run the engine at 2500 RPM.
- Turn ON the accessories.
- Load the battery using a carbon pile in order to obtain maximum amperage.
- Maintain the voltage at 13 volts or above.
- If the output is within 15 amperes of the rated output, the generator is working properly.
- If the output is not within 15 amperes of the rated output, replace the generator.
A reading other than B+ indicates one of the following faults between the terminal and the battery:
| • | An open circuit |
| • | A high resistance |
| • | A grounded circuit |
If the voltage is above 16 volts, replace the generator.
Caution: Unless directed otherwise, the ignition and start switch must be in the OFF or LOCK position, and all electrical loads must be OFF before servicing any electrical component. Disconnect the negative battery cable to prevent an electrical spark should a tool or equipment come in contact with an exposed electrical terminal. Failure to follow these precautions may result in personal injury and/or damage to the vehicle or its components.
