Modern diesel equipment relies heavily on electronic control systems. A mechanic who can diagnose both the mechanical problem and the electronic cause has a significant advantage.

A good starting point is learning:

• Basic DC electrical principles
• Sensors and actuators
• Electronic control modules
• Reading wiring diagrams
• Using a multimeter correctly
• Voltage-drop testing
• Continuity and resistance testing
• Understanding CAN-bus basics
• Reading and interpreting fault codes

What can you do right now?

If you work on mining or earthmoving equipment, identify the manufacturers you encounter most often — for example Caterpillar, Komatsu, Volvo, Bell or Sandvik — and find out what diagnostic systems they use. For Caterpillar equipment, for example, Cat Electronic Technician (Cat ET) is used by technicians to communicate with electronic control modules and diagnose machine systems. Caterpillar also provides online training through its Technicians for the World programme, covering fundamentals including mechanics, engines and electricity.

Caterpillar – Technicians for the World

Your practical goal: Don't just learn how to read a fault code. Learn how to use the code as the starting point for a proper diagnostic process.

Once you understand the fundamentals, go deeper into the diagnostic equipment used by the OEMs you work with. This is where your training should become equipment-specific.

For example, if you regularly work on Caterpillar equipment, learning how to use Cat ET is more immediately useful than taking a random generic electronics course. If you work predominantly on Komatsu equipment, investigate the diagnostic tools and training available for Komatsu equipment.

The principle is simple:

Don't collect certificates. Learn the systems you're actually going to use.

Ask your employer, workshop manager or equipment dealer: “What diagnostic software and equipment do our technicians use, and where can I get trained on it?” That is a practical conversation that can lead directly to your next skill.

Once you're comfortable with electronic diagnostics, the next step is understanding telematics.

Modern mining equipment can generate huge amounts of operational information.

As a diesel mechanic, you don't need to become a data scientist. You need to understand how this information can help you diagnose and maintain equipment.

Start learning about:

• Machine operating hours
• Engine performance data
• Fault events
• Fuel consumption
• Idle time
• Component temperatures
• Machine utilisation
• Maintenance alerts
• Remote diagnostics

For example, learn how telematics systems such as Cat Product Link and VisionLink are used to monitor equipment.

Your practical goal: The next time you see a machine report or telematics dashboard, don't just look at the information — ask what it means mechanically.

A fitter's ability to measure accurately is fundamental, but modern maintenance increasingly requires very precise measurement and tolerances.

A fitter should be comfortable using:

• Vernier calipers
• Micrometers
• Dial indicators
• Bore gauges
• Feeler gauges
• Depth gauges
• Torque wrenches
• Basic geometric measurement equipment

But don't stop at knowing how to use the instrument.

Learn to understand tolerances, fits and clearances and how incorrect measurements affect machinery.

What can you do?

Take a machine or component you work with and look at its manufacturer's specifications.

For example:

What is the specified shaft diameter?
What is the bearing clearance?
What is the allowable tolerance?

Then compare the specification with the actual measurement.

That is practical experience you can use on the job.

Where can you develop this?

Mitutoyo South Africa offers metrology training covering measurement principles and the correct use of measuring equipment.

Mitutoyo South Africa – Training

If you are a millwright and you don't understand PLCs yet, this is probably the best place to start.

Learn:

• What a PLC does
• Digital and analogue inputs and outputs
• Sensors
• Relays
• Timers and counters
• Ladder logic
• Basic PLC troubleshooting
• How a PLC communicates with other equipment

You don't initially need to learn advanced programming. You need to understand what the PLC is doing and how to troubleshoot the equipment around it.

Where can you learn it?

Siemens SITRAIN offers PLC training, including introductory courses covering PLC control principles, inputs and outputs, timers, counters and ladder programming.

Siemens SITRAIN South Africa

What can you do at work?

If your plant has PLC-controlled machinery, find out:

• Which PLC manufacturer do we use?

It might be Siemens, Allen-Bradley/Rockwell Automation, Schneider Electric or another system. Once you know, focus your training on that platform. Don't spend money learning three different PLC platforms at the beginning. Learn the one you're most likely to encounter at work.

Knowing PLC theory is useful. Being able to use it when a machine stops working is much more valuable. Imagine a conveyor won't start. A traditional approach might be:

"The motor isn't running."

A millwright with PLC knowledge starts asking:

Is the PLC receiving the start command?

Is the emergency stop circuit healthy?

Is the motor starter receiving the signal?

Is a safety interlock preventing the machine from starting?

Is a sensor giving the correct input?

Is the PLC output switching?

Is the problem electrical, mechanical or part of the control logic?

That's the skill you want to develop.

Your practical next step

The next time an automated machine develops a fault, ask to work through the troubleshooting process with the electrician, automation technician or controls engineer.

Look at the PLC inputs and outputs.

Find out:

• What should the machine be receiving?
• What is it actually receiving?
• Where does the signal stop?

That is real-world PLC troubleshooting experience.

Most modern automated equipment has an HMI — Human-Machine Interface.

It's the screen operators and technicians use to interact with the machine. A millwright should understand how to interpret the information displayed on the HMI.

Learn to identify:

• Machine status
• Alarm messages
• Fault history
• Sensor status
• Equipment sequences
• Setpoints
• Trends
• Manual/automatic modes
• Interlocks

What can you do?

The next time you see an alarm on an HMI, don't simply reset it.

Find out:

• Why did the alarm occur?
• Which sensor triggered it?
• What condition does the PLC require before the machine can restart?

That turns an HMI from a screen you look at into a diagnostic tool. Siemens provides training through SITRAIN covering automation and HMI technologies.

Siemens SITRAIN Training

This is where many technicians can significantly expand their knowledge.

Modern industrial equipment doesn't consist of isolated components. PLCs, HMIs, drives, sensors and other controllers can communicate over industrial networks.

A millwright should understand the basics of:

• Ethernet
• IP addresses
• Network switches
• PLC communication
• Remote I/O
• Industrial Ethernet
• Basic network troubleshooting

You don't need to become a network engineer. You need to understand enough to answer questions such as:

"The PLC is working, but why isn't it communicating with the remote I/O?"

or:

"Why has the HMI lost communication with the PLC?"

Your practical next step

Ask your automation department or controls technician:

"What communication protocols do we use on our plant equipment?"

Then learn those systems. For example, depending on the equipment, you might encounter technologies such as PROFINET, EtherNet/IP, Modbus TCP or PROFIBUS. Learning the technology actually used at your workplace is far more useful than learning networking in isolation.

This is another practical skill I'd strongly recommend for millwrights. Variable Frequency Drives, or VFDs, are commonly used to control motors.

Learn:

• What a VFD does
• Basic configuration
• Motor parameters
• Frequency and speed
• Fault codes
• Overcurrent faults
• Overvoltage/undervoltage
• Acceleration and deceleration
• Basic troubleshooting

A millwright who understands the interaction between the motor, VFD, PLC and mechanical equipment can troubleshoot much more effectively.

Your practical next step

Find out which VFD brands are used at your workplace. Then investigate training from that manufacturer. For example, Siemens offers training around drives and automation through SITRAIN.

Siemens SITRAIN South Africa

Again, learn what you actually encounter at work first.

This is where all the previous skills start coming together. Consider a conveyor that keeps stopping.

A basic approach might be:

Machine stopped → replace component → restart.

A stronger millwright approach is:

Machine stopped → check fault history → check HMI → check PLC inputs → check sensors → check VFD → check motor → inspect mechanical system → identify root cause.

You are no longer troubleshooting individual components.

You're troubleshooting the entire system. That's the real value of combining mechanical, electrical and automation skills.

Realistic Millwright Progression:

Millwright
↓
PLC Fundamentals
↓
PLC Fault-Finding
↓
HMI & Machine Diagnostics
↓
Variable Frequency Drives
↓
Industrial Networking
↓
Advanced Automation & Controls

You don't need to become an automation engineer. The objective is to become a millwright who understands automation well enough to diagnose modern industrial equipment.

What should a millwright do this month?

• This week: Find out which PLCs are used in your workplace.
• This month: Start an introductory PLC course.
• Next 3–6 months: Get practical experience troubleshooting PLC inputs, outputs and machine interlocks.
• Next 6 months: Learn the HMI and VFD systems used on your equipment.
• Next 6–12 months: Learn the industrial communication protocols used in your plant.

Then keep building from there.

The biggest advantage a millwright has is that you already understand the physical machinery. Add automation knowledge to that foundation, and you become much better equipped to troubleshoot the machines that are becoming increasingly common in modern mining and industrial operations.

Start with the systems you work with every day. A mining auto electrician should be confident working with:

• Starting systems
• Charging systems
• Batteries and battery management
• Alternators
• Starters
• Relays and contactors
• Fuses and circuit protection
• Sensors
• Actuators
• Electronic control modules
• Wiring harnesses
• Electrical schematics
• Voltage-drop testing
• Continuity and resistance testing
• Short-circuit and open-circuit diagnosis

The important part is learning to diagnose before replacing components.

For example, if a machine won't start, don't immediately assume the starter is faulty.

Work through the system:

Battery → isolator → protection → control circuit → starter relay/contactor → starter → engine

Determine where the electrical supply or control signal is being lost.

Your practical next step

Take a machine you work on regularly and choose one electrical system.

Get the manufacturer's wiring diagram and trace the complete circuit.

Identify:

• Where does the power come from?

• Which component controls it?

• Which sensors or switches are involved?

• Where does the circuit terminate?

Doing this with equipment you actually work on is far more useful than learning electrical theory without applying it.

This should be a priority for a mining auto electrician who wants to work with newer equipment. Modern heavy equipment contains multiple electronic control units that need to communicate with each other.

CAN-bus provides the underlying communication network, while SAE J1939 is a communication protocol widely used in heavy-duty vehicles and equipment.

You should understand:

• CAN High and CAN Low
• Termination resistance
• CAN communication
• J1939 fundamentals
• Electronic Control Units (ECUs)
• Network faults
• Communication errors
• Open circuits
• Short circuits
• Network resistance
• How a failed ECU or wiring fault can affect other systems

Your practical next step

Find out which CAN/J1939 systems are used on the equipment you work on. Then ask an experienced auto electrician or diagnostic technician to show you how they diagnose a communication fault. Don't just learn what CAN-bus is. Learn how to test it when something goes wrong.

Once you understand the electrical network, you need to become comfortable using diagnostic equipment. Modern mining equipment can generate large amounts of diagnostic information.

You should learn how to:

• Read diagnostic trouble codes
• View live data
• Check sensor values
• Monitor engine parameters
• Check communication between control modules
• Perform diagnostic tests
• Monitor system status
• Identify intermittent faults
• Confirm that a repair has actually solved the problem

The important distinction is:

A fault code is not necessarily the faulty component.

If an ECU reports a sensor fault, you still need to determine whether the problem is:

The sensor → wiring → connector → power supply → ground → communication → ECU

Replacing the sensor without testing the circuit can simply waste time and money.

Your practical next step

The next time a machine generates a diagnostic code, don't stop at reading the code.

Find out:

• What caused it?

• What should the sensor or system be reading?

• What is it actually reading?

• Can you prove where the fault is?

That is the difference between using diagnostic equipment and actually being good at diagnostics.

Once you have the fundamentals, start learning the diagnostic software used by the manufacturers whose equipment you work on. For example, Caterpillar equipment can be diagnosed using Cat Electronic Technician (Cat ET).

Other manufacturers have their own diagnostic platforms.

The important thing is to learn the systems relevant to the equipment you actually work on.

Your practical next step

• Look at the machines in your current workplace.

• Make a list of the major manufacturers you work with.

Then ask:

• What diagnostic software does this manufacturer use?

• Does the dealer provide training?

• Does my employer provide access to the software?

• Can I get practical experience using it?

Caterpillar provides technical training and resources through its dealer and technician network.

Caterpillar Technician Resources

Caterpillar also provides its Technicians for the World online programme, which covers fundamentals including mechanics, engines and electricity.

Caterpillar – Technicians for the World

If you work primarily on Komatsu, Sandvik, Epiroc, Volvo, Bell or another manufacturer's equipment, investigate training specific to that equipment instead.

The principle is simple: learn the equipment you actually want to work on.

This is where your electrical knowledge starts connecting with equipment data. Modern mining equipment can collect and transmit information about how the machine is operating. Depending on the system, this can include:

• Engine information
• Machine hours
• Fuel consumption
• Idle time
• Fault events
• Component information
• Machine utilisation
• Location
• Performance data
• Maintenance information

For a mining auto electrician, it is useful to understand where this information comes from and how it gets from the machine to the monitoring system.

For example, Caterpillar's equipment-management technology includes Product Link and VisionLink for collecting and analysing machine information.

Caterpillar Equipment Management Technology

Your practical next step

If your mine uses telematics, ask to see the system.

Find out:

• Which control module provides the information?

• How does the machine transmit it?

• What happens when communication is lost?

• Which faults are reported remotely?

This will help you understand how the electrical systems you work on connect to the mine's wider equipment-management system.

Safety technology is another area worth understanding. Mining operations increasingly use electronic systems designed to improve awareness of people, vehicles and equipment operating in the same environment. Depending on the operation, these systems can involve:

• Proximity detection
• Collision warning
• Collision avoidance
• Machine-to-machine communication
• Tracking
• Cameras
• Radar
• Detection sensors
• Operator alerts

As an auto electrician, your role may involve installing, maintaining, testing or troubleshooting some of these systems.

Your practical next step

Find out what proximity or collision-warning technology is used at your mine.

Ask the responsible technician or safety/technology team:

• What system is installed?

• What components are fitted to the machine?

• How does the system communicate?

• What happens when a sensor or communication connection fails?

Understanding these systems can give you another specialised area to build into your skill set.

Mining is also moving towards greater levels of equipment automation.

You don't need to become an automation engineer. But if you work on mobile mining equipment, understanding the basics of automated systems can prepare you for where the industry is heading.

Start learning about:

• Automated machine functions
• Remote operation
• Machine-control systems
• Sensors
• Machine positioning
• Communication systems
• Automated haulage
• Autonomous equipment
• Remote diagnostics

Your electrical and electronic background gives you a good starting point because these systems depend heavily on sensors, control modules, communication and electrical infrastructure.

Your practical next step

If your employer operates automated or autonomous equipment, find out which systems are being used. If it doesn't, follow the technology being introduced by the major mining-equipment manufacturers and learn the basic principles. You don't need to master the technology immediately. You need to understand what it does and what skills technicians will need to maintain it.

Mining Auto Electrician
↓
Heavy Equipment Electrical Systems
↓
CAN-Bus & J1939
↓
Electronic Diagnostics
↓
OEM Diagnostic Systems
↓
Telematics
↓
Proximity & Collision-Avoidance Systems
↓
Automation & Autonomous Equipment

You don't have to complete every course or become an expert in every technology.

The objective is to progressively add skills that build on your existing trade.

• This week: Identify the main equipment manufacturers you work with.

• This month: Strengthen your CAN-bus, J1939 and electronic diagnostic knowledge.

• Next 3–6 months: Get practical experience using the OEM diagnostic system used on your equipment.

• Next 6–12 months: Learn how your mine uses telematics and machine data.

After that: Choose one specialist area — such as proximity detection, collision avoidance or automated equipment — and develop your knowledge.

The mining auto electrician of the future will still need strong electrical fundamentals. But they will also need to understand electronics, communication networks, diagnostics and increasingly sophisticated machine technology.

You don't need to leave your trade to keep up with the industry. Build on it.