IK0800403 ­ Alternator Troubleshooting and Diagnostics

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Document
IK0800403
ID:

Availability: ISIS, NotSIR

Revision: 17

Major
System:

ELECTRICAL SYSTEM

Created:

11/1/2012

English

Last
Modified:

6/15/2017

Author:

Andrew
Boyd

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35

8

Title : Alternator Troubleshooting and Diagnostics
Applies To : All

CHANGE LOG
06/15/2017 - Corrected cable drop specs.
08/11/2015 - Added alternator terminal identification charts.
04/10/2015 - Changed warranty authorization code to charge code, adjusted note under description. Added Charge Code Location picture as
appendix E
04/02/2015 - Added information on how to find Alternator WAC on MidTronics




DESCRIPTION
This document details the procedure that must be followed to assure proper Alternator troubleshooting and diagnostics.
The procedure requires the use of the Midtronics EXP Tester, and Alternator Diagnostic Worksheet.
NOTE: Midtronics Warranty Authorization Codes, and Charging System Charge Codes are now required on every
Navistar Warranty Alternator replacement (excluding 55 over the counter parts).

FAULT CODES/SYMPTOMS
Overcharging
Undercharging
Fluctuating Battery Gauge
red battery warning light
Customer Concern:
Low battery system voltage
Red battery warning light
Batteries aren't Charging
Battery gauge reading too high
Battery gauge reading too low
Battery gauge fluctuating

SPECIAL TOOLS or SOFTWARE

Tool Description

Tool
Number

Comments

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IK0800403 ­ Alternator Troubleshooting and Diagnostics

Midtronics EXP
Tester

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EXP1000HD

Digital Multimeter

DIAGNOSTICS
Step Action

Decision

Feature code confirmation : Power Pack 3 Alternator
1

Yes: Go to Power Pack 3
Does this vehicle have a Power Pack 3 alternator--DuraStar or WorkStar with Diagnostics linked Here
feature code 60AJN, 60AJP,60AAC, or 60AAE?
For further information on this feature click here

Step Action
Inspect accessory drive belt for the following :

2

No: Go to Step 2

Decision

Yes: Go to Step 3

­ Excessive cracking
­ Missing/torn ribs
- Excessive edge wear
­ Contamination
Note: belts may not be covered under warranty--verify warranty policy.

No: Replace Belt, and
retest

Is the accessory drive belt usable?

Step Action

Check accessory drive belt auto tensioner for the following:

3

- Does the auto tensioner pulley spin freely?
- Does the tensioner arm move smotthily through its entire range of motion?
- Is there spring tension through the entire range of motion?
- Is the tensioner, at a mid-point, within its range of travel?
- Inspect for loose Alternator Pulley

Decision

Yes: Go to Step 4

No: Replace accessory drive
belt auto tensioner and retest

Was "yes" the answer to ALL of the previous questions?

Step Action
Inspect alternator cables and connections for the following :

4

­ Loose crimps
- Corrosion
­ Damage
- Proper routing

Decision
Yes: Go to Step 5

No: Repair/Replace any
defective Alternator Cables
and Connections and retest

Are all alternator cables and connections free of issues?

Step Action

If the Alternator has an ignition (IGN) terminal, there must be power present at all times.
5

Yes or not present, Go to Step
6

Use a volt meter to measure voltage at the terminal.
Is the voltage reading 12.4V or greater?

Step Action
6

Decision

No: Find Circuit issue and
repair. Then Retest.

Decision

If the Alternator has a battery voltage sensing feature.
Yes: Go to Step 7
• Verify that the sense wire is securely connected to the "S" (Sense) Terminal
• Visually inspect circuit to the batteries, to verify the circuit is not damaged.
See Appendix D for illustration describing the issue

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IK0800403 ­ Alternator Troubleshooting and Diagnostics

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Note : If voltage sense is not equipped on the alternator go to Step 7. The voltage sense
wire should NOT be connected to the "L" (Lamp) Terminal

No: Reinstall/repair Voltage
Sensing Wire to appropriate
terminal and then retest

Note : For further terminal information see Appendix F.
Is Voltage Sensing Wire hooked up correctly, and not damaged?
Step Action

Decision

Battery Pack Breakdown Test
1. Do the "Test Preparation" as described in Section 4 of the Midtronics EXP Instruction
Manual.

Good Battery(s) : Go to Step 8

2. Select "System Test" and follow procedure for testing battery individual battery, as
described in Section 5 of the Midtronics EXP Instruction Manual
7

Note : Do not test as a pack. Test batteries individually.
Replace/Bad Cell : Replace
Note : Use Midtronics battery stud adaptors on each battery tested. Failure to do so will yield bad batteries and re­
inaccurate results.
perform Step 7
Note : Keep all generated warranty codes during testing to later be submitted on Warranty
Claim (If warranty applies)
Charge and Retest : Charge
batteries and reperform Step 7
What were the individual test results for each Battery?

Step Action

Decision

Starter and Alternator System Test
Continue with Midtronics System Test, Section 5, for Starter and Alternator :
1. Connect positive (+), and negative (-) test leads to batteries
2. Following Midtronics prompts, conduct "Starter System Test" and "Charging System
Test"
8

Yes: Replace alternator and
retest for condition.

3. When prompted choose 'Amp Clamp Available' option if available
Note : Record Midtronics Charge Code generated for warranty submission (See
Appendix E for Charge Code Location).
Note : Midtronics Charge Code can be found by using the down arrow on the key
pad after Charging System portion of the test is completed.
No: Go to Step 9
Was a problem with the alternator detected?

Step Action

Decision

Circuit Test (If Midtronics Cable Drop Test Leads) are available :
Note : If Midtronics Cable Drop Test Leads are not available go to Step 10
1. Connect the Midtronics Cable Drop Test Leads
9

Yes: Repair Charging System
Cable(s) as needed, and Retest.

2. Perform the Cable Drop Test as described in Section 7 of the Midtronics Manual
3. Record indicated Voltage drops from each cable on the Midtronics tool, into the
Alternator Diagnostic Worksheet.
No: Go to Step 10
Is the sum of cable drop between each cable greater than 0.5V (+/- 0.25V)?

Step Action

Decision
Yes: Go to Step 11

Feature Code Confirmation : Leece Neville Alternator

1. Does this vehicle have a Leece Neville Alternator with feature code 08GXD,
08GXE, 08GXC, or 08GXB?

No: Go to Step 12, if cable drop
wasn't possible at Step 9

10
2. Was this vehicle also built between 08/2013 - 03/2014?

Does the vehicle have this feature code, and fall in this build date range?

No : If cable drop was possible in