GM Service Manual Online
For 1990-2009 cars
Makes 🢒 Chevrolet 🢒 2004 🢒 Tahoe - 2WD 🢒 Engine 🢒 Engine Electrical 🢒 Charging System Test

Charging System Test CS/AD/SI Generators

Step

Action

Value(s)

Yes

No

1

Did you perform the Engine Electrical Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Engine Electrical

2

Start the engine. Observe the charge indicator on the instrument cluster (IPC) .

Does the charge indicator illuminate or message center (DIC) display a charging system message?

--

Go to Step 3

Go to Symptoms - Engine Electrical

3

Important: The green POWER lamp of the tester should remain illuminated while the tester is being used.

  1. Turn OFF the ignition.
  2. Connect the red lead of the J 41450-B Universal CS Generator Test Harness to the generator output terminal.
  3. Connect the black lead of the J 41450-B to the metal generator housing.

Does the green POWER lamp on the tester illuminate?

--

Go to Step 6

Go to Step 4

4

Measure the voltage from the output terminal of the generator to the generator metal housing.

Does the voltage measure equal to the specified value?

12.0 V

Go to Step 14

Go to Step 5

5

Measure the voltage from the output terminal of the generator to the battery negative terminal.

Does the voltage measure equal to the specified value?

12.0 V

Go to Step 12

Go to Step 11

6
  1. Turn OFF completely the load tool before connecting or disconnecting a carbon pile load tester to the battery. Otherwise, sparking at the terminals could cause battery gasses to explode.
  2. Connect a carbon pile tester to the vehicle.

    3. Important: Ensure that all generator output circuit wires pass through the inductive probe.

  3. Connect an inductive ammeter to the output circuit of the generator.
  4. Disconnect the generator harness connector.
  5. Locate the matching harness connector on the J 41450-B , and connect the connector to the generator.

Does the red DIAGNOSTIC lamp on the tester illuminate?

--

Go to Step 7

Go to Step 13

7
  1. Start the engine and allow it to idle for 30 seconds.
  2. Increase the engine speed to 2,500 RPM.

Does the red DIAGNOSTIC lamp on the tester illuminate?

--

Go to Step 15

Go to Step 8

8
  1. Maintain the engine speed at 2,500 RPM.

    2. Important: If the generator is not capable of producing the Load Test amps, operate the generator at it's maximum possible output.

  2. Turn ON the load of the carbon pile tester and increase the load until the generator output is equal to the Load Test value given in Generator Usage.

Does the red DIAGNOSTIC lamp on the tester illuminate?

--

Go to Step 15

Go to Step 9

9
  1. Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value.
  2. Measure the voltage drop from the output terminal of the generator to the positive terminal on the battery. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.5 V

Go to Step 11

Go to Step 10

10
  1. Maintain the engine speed at 2,500 RPM and continue to operate the generator at the load test value.
  2. Measure the voltage drop from the battery negative terminal to the metal housing of the generator. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Does the voltage measure greater than the specified value?

0.5 V

Go to Step 12

Go to Step 16

11

Repair the high resistance or an open in the output circuit of the generator. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

12

Repair the high resistance or open in the ground circuit of the generator. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you complete the repair?

--

Go to Step 16

--

13
  1. Disconnect the J 41450-B tester harness connector from the generator, but leave the alligator clips connected so that the green POWER lamp remains illuminated.
  2. Connect a jumper lead, with an in-line 100-ohm resistor between the J 41450-B tester harness connector terminal B of the generator and a good ground. Refer to Engine Electrical Connector End Views .

Does the red DIAGNOSTIC lamp illuminate?

--

Go to Step 15

Go to Step 14

14

There is a problem with the J 41450-B . Refer to the manufacturers instructions, how to test the J 41450-B for proper operation.

Has the J 41450-B tester been replaced?

--

Go to Step 3

--

15

Replace the generator. Refer to Generator Replacement .

Did you complete the replacement?

--

Go to Step 16

--

16

Operate the vehicle in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2