1. Reducing Electrical Cost and Minimizing Downtime
Brian Thompson
National Fleet Manager
4/23/17

2. Today’s Issues Staying Ahead of the Curve for Electrical Requirements
EPA regulations
Idle restrictions causing major increase in starts/stops and lack of run time
Battery and reserve capacity demands
Driver Habits and Demands

3. Reducing Cost & Minimizing Downtime
Troubleshooting
Industry standard of good parts returned 25-30%
Leads to improper diagnosis resulting in repeat road call/towing
Test Equipment – Voltage Drops
System Design/Specifications
TMC RP 129A
Understanding Electrical Applications
Alternator Output Requirements
Battery Reserve Capacity
System Maintenance
Corrosion
Loose Connections/Crimps etc

4. The Electrical System Basics
Specing Basic Steps
Always treat as a system
Spec the right components for your needs
Understand you applications
Troubleshooting Basic Steps
Visual Inspection
Always start with the batteries
Batteries should be at least 12.4 volts and test good before proceeding
Test cables and circuits
Proceed to components

5. Heavy Duty Electrical System

6. Batteries Provide Power to Start Provide Power for Accessories
Regulate the Voltage of the System
Limited Power Supply

7. Batteries
CCA – Cold Cranking Amperes – A measure of the batteries ability to give a quick burst of power at cold temperatures (Cranking the Engine)
RC – Reserve Capacity – A measure of the batteries ability to cover loads while there is no alternator output. ( Lights, Inverter, etc.)

8. Batteries – Lead Acid

9. Batteries

10. Batteries
Cycle is discharge to 80% (12.4)

11. Batteries
Generally Batteries at a low state of charge can consume Amps each if available
3 Battery System – Amps
4 Battery System – Amps
LVD Set-points 12.1 – 11.8 
State of Charge
Sealed or Flooded Lead Acid
Gel battery
AGM battery
100%
12.70+
12.85+
12.80+
75%
12.40
12.65
12.60
50%
12.20
12.35
12.30
25%
12.00 0%
11.80

12. Battery Testing Testing with Carbon Pile Load Tester
Use testing adapters!
Remove surface charge by applying 300 amp load for 15 seconds
Read terminal voltage of battery. If 12.4V or better proceed to next step.
If less than 12.4V recharge battery and repeat surface charge removal
Adjust carbon pile to apply one half of the CCA rating.
Maintain load for 15 seconds and record terminal voltage.
Estimate battery temperature and refer to chart on next page.

13. Battery Testing Estimated Battery Temp Voltage Not to Fall Below
70F or 21C V
60F or 16C V
50F or 10C V
40F or 4C V
30F or –1C V
20F or –7C V
10F or –12C V
0F or –17.8C V

14. Cables TMC – System Recommendations
Alternator Circuit
.5Volt Alternator Rated Output
Starter Circuit
.5Volt 500 Amps

15. Alternator Spec Considerations
How long are you going to keep your truck?
Brush versus Brushless
Brush style – Typical low cost standard Alternator
Brushless – Premium – Longer Life
Brushless – fewer moving parts for improved durability
How many amps do you need?
Output / output at idle
Indentify application requirements
High out applications
Remote Sense for improved battery charge time and life
Over spec’ing provides longer system and alternator life
Fuel economy – high efficiency alternators designed for substantial savings

16. Performance

17. Remote Sense

18. Alternator Feature Focus – High Efficiency
60%vs 68%
60%vs 75%
Higher Efficiency = Less Horsepower Draw From the Engine

19. Alternator Trouble Shooting

20. Alternator Trouble Shooting
Cable Drop Test Using Load Tester
With engine off connect leads of load tester to alternator output terminal and ground.
Connect a separate voltmeter to the batteries
Adjust load tester to the rated output of alternator
Read voltage at load tester and read voltage at separate voltmeter.

21. Alternator Trouble Shooting
Load Tester Voltage Drop Results
Voltmeter Reading At Battery – Voltmeter Reading At Alternator = Total Voltage Drop
12.4V
11.1V
=1.3V drop
The Maximum Allowable Voltage Drop is .5V

22. Alternator Trouble Shooting
Determining which cable has the problem
Move the positive lead of the voltmeter at the battery to the ground post on alternator.
Connect negative lead of voltmeter to negative post of the battery.
Adjust load tester to full rated output of alternator.
Record reading at separate voltmeter.
Note! The use of small jumper cables for your voltmeter to reach connections is allowed

23. Alternator Trouble Shooting
Determining which cable has the problem
Move the negative lead of the voltmeter at the battery to the positive post on alternator.
Connect positive lead of voltmeter to positive post of battery.
Adjust load tester to full rated output of alternator.
Record reading at separate voltmeter.

24. Alternator Trouble Shooting
Load Tester Voltage Drop Results
Voltmeter Reading for ground side
Plus – Voltmeter Reading for positive side
Equals – Total Voltage Drop
.9V
+ .4V
=1.3V drop
Again
The Maximum Allowable Voltage Drop is .5V

25. Starter Spec Considerations
Over Crank Protection (OCP) (Typical 3yr/350K Warranty)
Cold cranking speed performance
Weight
Voltage drops (based on TMC Recommended Practice (RP) 129
Loss results in .5v = 15 engine RPM
Integrated Magnetic Switch (IMS)

26. Starter Trouble Shooting

27. Starter Trouble Shooting
TMC Recommendations – Control Circuit Volt Drop
Delco - Remy

28. Starter Trouble Shooting

29. Starter Trouble Shooting

30. Starter Trouble Shooting
Drop = .3 Volts
Load Tester
11.0
12.4
100 2 3 1 4
Delco - Remy

31. Starter Trouble Shooting
Total Voltage Drop 1.4Volts
Leg 1 (1 – 2 ) .5 Volts
Leg 2 (3 – 4 ) .3 Volts
Mag Switch (2 – 3) .6 Volts
TMC Recommendation is 1.0 volt max

32. Summary Treat as a System Understand your application
Battery
Cables
Component
Understand your application
Always start at the batteries

33. Summary
Questions?

34. Thank You For Your Attention
Our Vision
A Clean, Energy-Efficient World
Our Mission
Deliver Innovative Powertrain Solutions that Improve Fuel Economy, Emissions & Performance
Fuel Economy
Emissions
Performance