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Makes 🢒 GMC_Truck 🢒 1998 🢒 GMC P42 Commercial Chassis 🢒 Engine 🢒 Engine Electrical 🢒 Battery Is Undercharged or Overcharged

Battery Is Undercharged or Overcharged P32

Step

Action

Value(s)

Yes

No

1
  1. Disconnect the generator connector.
  2. Turn the ignition switch to the RUN position.
  3. Probe the generator connector with a J 39200 from cavity S to ground.
  4. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 2

Go to Step 3

2

Locate and repair the open in CKT 2 (RED) between the fusible link and the generator connector, cavity S.

Is the repair complete?

--

System OK

--

3
  1. Probe the generator with a J 39200 from the BAT terminal to ground.
  2. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 4

Go to Step 5

4

Locate and repair the open in CKT 2 (RED) between the fusible link and the generator BAT terminal.

Is the repair complete?

--

System OK

--

5
  1. Probe the generator connector with a J 39200 from cavity I to ground.
  2. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 6

Go to Step 7

6

Locate and repair the open in CKT 39 (PNK) between the IP fuse block and the generator.

Is the repair complete?

--

System OK

--

7
  1. Connect the generator connector.
  2. Ensure that all of the accessories are turned OFF and the engine is running at fast idle.
  3. Probe the battery with a J 39200 from the positive (+) terminal to the negative (-) terminal.
  4. Measure the voltage.

Does the voltage measure 13-16 volts?

13-16 V

Go to Battery Not Operating Properly .

Go to Step 8

8
  1. Do a generator bench test. Refer to Generator Assembly Bench Check .
  2. If the generator is OK, do a battery load test. Refer to Battery Not Operating Properly .

Is the repair complete?

--

System OK

--

Battery Is Undercharged or Overcharged P42

Step

Action

Value(s)

Yes

No

1
  1. Disconnect the generator connector.
  2. Probe the generator connector with a J 39200 from cavity S (124 or 145 amp) or D (Base, 105 amp) to ground.
  3. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 2

Go to Step 3

2

Repair or replace the CKT 2 (RED) wire between the fusible link and the generator connector.

Is the repair complete?

--

System OK

--

3
  1. Probe the generator connector with a J 39200 from the BAT terminal to ground.
  2. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 4

Go to Step 5

4

Repair or replace the CKT 2 (RED) wire between the fusible link and the generator.

Is the repair complete?

--

System OK

--

5
  1. Turn the ignition switch to the RUN position.
  2. Probe the generator connector with a J 39200 from cavity F (124 or 145 amp) or C (Base, 105 amp) to ground.
  3. Measure the voltage.

Does the voltage measure less than 10 volts?

10 V

Go to Step 6

Go to Step 7

6

Locate and repair the open in CKT 39 (PNK) between the IP fuse block and the generator connector.

Is the repair complete?

--

System OK

--

7
  1. Turn the ignition switch to the OFF position.
  2. Connect the generator connector.
  3. Start the engine.
  4. Turn off all of the accessories and run the engine at fast idle.
  5. Probe the battery with a J 39200 from the positive (+) terminal to the negative (-) terminal.
  6. Measure the voltage.

Does the voltage measure between 13-16 volts?

13-16 V

Go to Battery Not Operating Properly .

Go to Step 8

8
  1. Do a Generator Bench Test. Refer to Generator Assembly Bench Check .
  2. If the generator is OK, do a battery load test. Refer to Battery Not Operating Properly .

Is the repair complete?

--

System OK

--