The John Deere 112 was introduced in 1966 and was available with a 38 inch or 46 inch mower deck. It was powered by a 10 hp Kohler engine and featured a 4-speed transmission. The wiring diagram for the 1968 model is important for any owner looking to make repairs or modifications to their tractor. In this article, we will discuss the wiring diagram in detail and provide helpful tips and FAQs for maintenance and repair.
Understanding the Wiring Diagram
The wiring diagram for the 1968 John Deere 112 can be found in the owner’s manual or service manual. It is a comprehensive diagram that includes all of the electrical components and their connections. The diagram is divided into sections based on the different parts of the tractor that require electrical power. These sections include the engine, ignition system, lighting system, charging system, and accessories.
Each section of the diagram is labeled with a letter and a number. The letter indicates the area of the tractor the section corresponds to, while the number indicates the specific wire or component. For example, “A1” refers to the first wire in the engine section, while “B3” refers to the third wire in the ignition system section.
The wiring diagram is essential for troubleshooting electrical issues on the tractor. If a component is not working, the diagram can help identify which wires to test and which components to check. It is also useful for making modifications or installing accessories that require electrical power.
The Engine Section
The engine section of the wiring diagram includes all of the wires that connect to the engine and its components. This includes the ignition system, starter, and charging system. There are several key components in this section that require attention, such as the voltage regulator, ignition coil, and spark plug wires.
The voltage regulator is responsible for regulating the charging system and preventing the battery from being overcharged. If the regulator fails, it can cause the battery to overcharge and potentially damage the electrical system. Testing the voltage regulator is important if there are charging issues or if the battery is not holding a charge.
The ignition coil converts the low voltage from the battery to a high voltage that is required to create a spark at the spark plug. If the coil fails or is weak, it can cause the engine to run poorly or not start at all. Testing the coil is important if there are ignition issues or if the engine is running poorly.
The spark plug wires connect the ignition coil to the spark plugs. If the wires are damaged or worn, it can cause the engine to misfire or run poorly. Testing the wires is important if there are ignition issues or if the engine is running poorly.
The Ignition System Section
The ignition system section of the wiring diagram includes all of the wires that connect to the ignition switch, key switch, and starter switch. This section also includes the wires that connect to the ignition coil and spark plugs. There are several key components in this section that require attention, such as the ignition switch, key switch, and starter switch.
The ignition switch is responsible for turning the engine on and off. If the switch fails, it can cause the engine to not start or turn off unexpectedly. Testing the switch is important if there are ignition issues or if the engine is not starting.
The key switch is responsible for controlling the accessories on the tractor, such as lights and the electric clutch for the mower deck. If the switch fails, it can cause the accessories to not work or work erratically. Testing the switch is important if there are accessory issues or if the accessories are working erratically.
The starter switch is responsible for engaging the starter motor when the key is turned. If the switch fails, it can cause the starter to not engage or engage erratically. Testing the switch is important if there are starting issues or if the starter is not engaging.
The Lighting System Section
The lighting system section of the wiring diagram includes all of the wires that connect to the headlights, tail lights, and other lighting components on the tractor. There are several key components in this section that require attention, such as the light switch, headlight bulbs, and wiring connectors.
The light switch is responsible for turning the headlights and tail lights on and off. If the switch fails, it can cause the lights to not work or work erratically. Testing the switch is important if there are lighting issues or if the lights are not working.
The headlight bulbs are responsible for providing light for the driver when operating the tractor in low light conditions. If the bulbs are burnt out, it can cause the driver to not be able to see well enough to operate the tractor safely. Testing the bulbs is important if there are lighting issues or if the lights are not working.
The wiring connectors are responsible for connecting the wires to the lighting components. If the connectors are corroded or damaged, it can cause the lights to not work or work erratically. Testing the connectors is important if there are lighting issues or if the lights are not working.
The Charging System Section
The charging system section of the wiring diagram includes all of the wires that connect to the voltage regulator, alternator, and battery on the tractor. There are several key components in this section that require attention, such as the alternator, voltage regulator, and battery cables.
The alternator is responsible for generating electrical power for the tractor while it is running. If the alternator fails, it can cause the battery to not charge and eventually run out of power. Testing the alternator is important if there are charging issues or if the battery is not holding a charge.
The voltage regulator is responsible for regulating the charging system and preventing the battery from being overcharged. If the regulator fails, it can cause the battery to overcharge and potentially damage the electrical system. Testing the voltage regulator is important if there are charging issues or if the battery is not holding a charge.
The battery cables connect the battery to the rest of the electrical system. If the cables are corroded or damaged, it can cause the battery to not charge or not supply power to the electrical system. Testing the cables is important if there are charging issues or if the battery is not holding a charge.
The Accessories Section
The accessories section of the wiring diagram includes all of the wires that connect to the electric clutch for the mower deck and other accessories on the tractor. There are several key components in this section that require attention, such as the electric clutch, wiring connectors, and switches.
The electric clutch is responsible for engaging and disengaging the mower deck. If the clutch fails, it can cause the mower deck to not engage or disengage erratically. Testing the clutch is important if there are mower deck issues or if the clutch is not engaging or disengaging properly.
The wiring connectors are responsible for connecting the wires to the accessories. If the connectors are corroded or damaged, it can cause the accessories to not work or work erratically. Testing the connectors is important if there are accessory issues or if the accessories are working erratically.
The switches control the various accessories on the tractor. If the switches fail, it can cause the accessories to not work or work erratically. Testing the switches is important if there are accessory issues or if the accessories are working erratically.
Frequently Asked Questions
| Question | Answer |
|---|---|
| What is the purpose of the wiring diagram? | The wiring diagram is used to understand the electrical connections on the tractor and troubleshoot any issues that may arise. |
| Where can I find the wiring diagram? | The wiring diagram can be found in the owner’s manual or service manual for the tractor. |
| How do I test a component? | Testing a component involves using a multimeter to check for continuity or voltage. The specific testing procedure will vary based on the component being tested. |
| What should I do if a component fails? | If a component fails, it should be replaced with a new one. It is important to use the correct replacement part to ensure proper operation of the electrical system. |
| How often should I check the wiring? | It is a good idea to check the wiring periodically for damage or wear. Checking the wiring during routine maintenance is recommended. |
In conclusion, the wiring diagram for the 1968 John Deere 112 is an important tool for any owner looking to maintain or repair their tractor’s electrical system. Understanding the different sections of the diagram and the key components within each section can help troubleshoot issues and make modifications or installations properly. By following the tips and FAQs provided in this article, owners can ensure their tractor operates safely and efficiently.
