John Deere 4020 Starter Wiring Diagram

The John Deere 4020 is a classic tractor that is still in use on farms around the world. One of the key components of this tractor is the starter, which is responsible for getting the engine running. In order to properly maintain and repair the starter, it is important to have a wiring diagram. In this article, we will provide a complete wiring diagram for the John Deere 4020 starter, along with frequently asked questions and troubleshooting tips.

Overview of John Deere 4020 Starter Wiring Diagram

The starter wiring diagram for the John Deere 4020 can be broken down into several different components. These include the battery, solenoid, ignition switch, starter motor, and starter relay. Each of these components plays a critical role in getting the engine started, and it is important to understand how they all work together.

Battery

The battery provides the power to the entire electrical system of the tractor, including the starter motor. In the wiring diagram, the positive terminal of the battery is connected to the solenoid, while the negative terminal is connected to the frame of the tractor.

Solenoid

The solenoid is a switch that is responsible for connecting and disconnecting the battery from the starter motor. In the wiring diagram, the solenoid is connected to both the battery and the starter motor, and is activated by the ignition switch.

Ignition Switch

The ignition switch is used to energize the solenoid and start the engine. In the wiring diagram, the ignition switch is connected to the solenoid, and also controls other electrical components on the tractor.

Starter Motor

The starter motor is responsible for turning over the engine and getting it running. In the wiring diagram, the starter motor is connected to both the solenoid and the battery, and is activated when the solenoid is energized by the ignition switch.

Starter Relay

The starter relay is an additional component that is used to protect the solenoid and other electrical components from damage. In the wiring diagram, the starter relay is connected to the solenoid and the ignition switch, and is activated when the key is turned to the “start” position.

FAQ: John Deere 4020 Starter Wiring Diagram

What size battery do I need for my John Deere 4020?

The John Deere 4020 typically requires a 12-volt battery with a minimum of 650 cold cranking amps. It is important to always use a high-quality battery that is designed for use with agricultural equipment.

How do I know if my solenoid is bad?

If your starter motor is not turning over, it may be a sign that the solenoid is bad. You can test the solenoid by using a multimeter to check for continuity between the terminals. If there is no continuity, the solenoid will need to be replaced.

What should I do if my starter motor is not turning over?

If your starter motor is not turning over, there may be several different issues at play. First, check to make sure your battery is fully charged and in good condition. You should also inspect all the wiring connections to make sure they are clean and tight. If these steps do not solve the problem, you may need to replace the starter motor or solenoid.

How can I get a replacement wiring diagram for my John Deere 4020?

You can typically find a wiring diagram for your John Deere 4020 in the owner’s manual or service manual. If you do not have access to these resources, you can contact a John Deere dealer or search online for a diagram.

Troubleshooting Tips for John Deere 4020 Starter Wiring Diagram

Problem: Engine does not start when key is turned

Possible causes: dead battery, faulty solenoid, bad starter motor

Solution: Check the battery to make sure it is fully charged and in good condition. Test the solenoid with a multimeter to check for continuity. If the solenoid is bad, replace it. If the solenoid is good, check the wiring connections to the starter motor. If the connections are good, test the starter motor for proper operation and replace if necessary.

Problem: Engine cranks slowly or does not crank at all

Possible causes: low battery voltage, corroded wiring connections, faulty starter motor

Solution: Check the battery voltage with a multimeter to make sure it is within the correct range. Check all wiring connections for signs of corrosion, and clean or replace as necessary. If the connections are good, test the starter motor for proper operation and replace if necessary.

Problem: Starter engages but engine does not start

Possible causes: fuel or ignition system issues, engine mechanical problems

Solution: Check the fuel system to make sure it is delivering fuel to the engine. Check the ignition system to make sure it is delivering spark to the spark plugs. If these systems are functioning properly, inspect the engine for mechanical problems such as low compression or a clogged air filter.

John Deere 4020 Starter Wiring Diagram
Component Wire Color Terminal Description
Battery Red Positive (+) Provides power to entire electrical system
Frame Black Negative (-) Grounds electrical system to frame of tractor
Solenoid White S Connects battery to starter motor
Solenoid Yellow I Connects solenoid to ignition switch
Ignition Switch Red B Connects battery to ignition switch
Ignition Switch Black A Connects ignition switch to solenoid and other electrical components
Starter Motor Black Ground (-) Grounds starter motor to frame of tractor
Starter Motor White Battery (+) Connects starter motor to battery
Starter Relay Green R Connects starter relay to ignition switch
Starter Relay Orange G Connects starter relay to solenoid

Overall, understanding the wiring diagram for the John Deere 4020 starter is essential for proper maintenance and repair of this classic tractor. By following the troubleshooting tips and regularly checking the components, you can ensure that your 4020 is running smoothly and efficiently.