Coolster 125cc ATV Wiring Diagram: A Comprehensive Guide

Coolster 125cc ATV Wiring Diagram: A Comprehensive Guide

If you’re a proud owner of a Coolster 125cc ATV, understanding its wiring diagram is essential for troubleshooting, maintenance, and customisation purposes.

A wiring diagram visually represents the electrical connections within your ATV, allowing you to identify various components and their interconnections. The details of the Coolster 125cc ATV wiring diagram will be covered in detail in this post.

The Basics

Before we dive into the details of the wiring diagram, let’s familiarise ourselves with some basic terms related to ATV electrical systems:


The battery is the power source for the ATV. It retains electrical energy and releases it to different components as required.

Starter Motor:

The starter motor initiates the engine’s rotation when you start the ATV. It draws power from the battery to crank the engine.

Ignition Switch:

The electrical system of the ATV may be turned on or off using the ignition switch.

CDI Box: 

The CDI (Capacitor Discharge Ignition) box is an essential component that controls the timing of the spark plug ignition. It receives signals from the ATV’s stator and delivers high-voltage electrical pulses to the spark plug.


The stator generates electrical energy when the engine is running. It comprises coils and magnets that create alternating current (AC), which the ATV’s regulator or rectifier converts to direct current (DC).


The regulator/rectifier converts the AC voltage generated by the stator into DC voltage and regulates its output to ensure a steady power supply to the ATV’s electrical system.

Wiring Harness: 

Electrical signals are sent between the various components of an ATV via a wiring harness, a configuration of wires and connections. It provides a neat and organised way to connect all the electrical parts.

Wiring Diagram Components

Now that we have a basic understanding of the key components, let’s examine the various elements you will typically find in a Coolster 125cc ATV wiring diagram:


The wiring diagram will indicate the battery’s location and its positive (+) and negative (-) terminals.

Ignition Switch:

Look for the ignition switch symbol, representing the device responsible for controlling the ATV’s electrical system. The connections between the ignition switch and other parts are displayed in the wiring diagram.

Starter Motor:

The connections between the ignition switch, battery, starting motor, and other pertinent components will be shown in the wiring diagram.

CDI Box:

The CDI box is a crucial component; its connections are clearly depicted in the wiring diagram. You will be able to identify the input and output terminals and the associated wires.


The stator’s wiring connections will be indicated in the diagram. Pay attention to the wires leading from the stator to the CDI box and regulator/rectifier.


The wiring diagram will show the regulator or rectifier’s position and connections to the stator, battery, and other components.

Wiring Harness:

The wiring diagram will provide specific information on the connections made by the wire harness, which forms the core of the ATV’s electrical system. Each wire colour and connector type will be identified, helping you understand how the different components are linked.

Troubleshooting with the Wiring Diagram

A wiring diagram becomes invaluable when troubleshooting electrical issues in your Coolster 125cc ATV. You can trace wires, identify faulty connections, and diagnose problems effectively by referring to the diagram. Here are a few common troubleshooting scenarios where the wiring diagram proves useful.

No Electrical Power: 

If your ATV fails to power on, you can trace the power flow using the wiring diagram. Check the battery, ignition switch, and associated wiring for any loose connections or damage.

Starter motor failure: 

If your ATV doesn’t start when you engage the starter, verify via the wiring diagram that the battery and ignition switch provide electricity to the starting motor.

Weak or No Spark:

If you’re experiencing issues with the spark plug, the wiring diagram can help you inspect the CDI box, stator, and associated wiring for any faults. Always exercise caution while troubleshooting electrical systems.

If you need more clarification or are uncomfortable with electrical work, consult a professional technician or refer to the official Coolster manuals for guidance.

Customisation and Modifications

If you intend to alter or modify your Coolster 125cc ATV, a thorough grasp of the wiring diagram may be beneficial. Whether you want to add additional lights, install a sound system, or make other electrical enhancements, referring to the wiring diagram ensures that you make the correct connections without damaging any components.

When customising your ATV, it’s essential to follow safety guidelines and adhere to local regulations. Always consult the wiring diagram and seek professional assistance if you need clarification on any modifications.

Accessing Wiring Diagrams

To access the official Coolster 125cc ATV wiring diagrams, it’s recommended to refer to the manufacturer’s website or contact your nearest authorised Coolster dealer. The official diagrams provide accurate and specific information tailored to your ATV model, ensuring you have the most up-to-date and reliable information.

Additionally, online ATV forums and communities may offer user-generated wiring diagrams and guides. While these resources can be helpful for reference purposes, exercise caution and cross-reference the information with the official Coolster diagrams to ensure accuracy.

Safety Precautions

When working with your Coolster 125cc ATV’s electrical system, prioritising safety is crucial. Here are some key safety precautions to keep in mind:

Disconnect the battery.

Disconnect the batteries before beginning any electrical operation to prevent unintentional electric shocks or short circuits.

Wear protective gear.

Put on the appropriate safety gear, such as goggles and gloves., when working with the electrical system to keep yourself safe from harm.

Proper insulation: 

Ensure that all connections are properly insulated using heat-shrink tubing, electrical tape, or other suitable methods. This helps prevent short circuits and ensures a secure and reliable electrical connection.

Consult a professional.

If you need clarification on any aspect of working with the electrical system or if you encounter a complex issue, it’s best to consult a professional technician who specialises in ATV electrical systems.


The Coolster 125cc ATV wiring diagram is essential for troubleshooting, maintenance, customisation, and modifications. You gain valuable insights into your ATV’s electrical system by familiarising yourself with the different components and their interconnections.

Safety should be your top priority when working with any electrical system. Always follow proper procedures, refer to official wiring diagrams, and consult professionals when needed. With the right knowledge and precautions, you can effectively maintain, troubleshoot, and customise your Coolster 125cc ATV.


What should I do if the ATV doesn’t start after wiring?

If your ATV fails to start after wiring, first check the battery for a secure connection. Ensure all wiring connections are correct and tight. Examine the ignition switch and fuse for any issues.

Confirm that the kill switch is in the proper position. If problems persist, consult the ATV’s manual or seek professional assistance to diagnose and resolve electrical issues.

Can I use a generic wiring diagram for my Coolster 125cc ATV?

Using a generic wiring diagram for a Coolster 125cc ATV may lead to incorrect connections or compatibility issues. It is advisable to use the manufacturer’s specified wiring diagram to ensure accurate information for your ATV model.

Generic diagrams might not account for model-specific variations, potentially causing electrical malfunctions. Refer to the Coolster 125cc ATV manual or contact the manufacturer for the correct wiring diagram to ensure proper installation and functionality.

Are there professional services available for wiring upgrades?

Yes, professional services specialise in ATV wiring upgrades for those who prefer expert assistance.

How often should I inspect the wiring system?

Regular inspections, at least every few months, are advisable to catch potential issues early.

Can we customise the wiring for additional accessories?

You can customise the wiring with the proper knowledge and expertise to accommodate additional accessories.

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