The 6.9 IDI is a diesel engine produced by Ford Motor Company from the late 1970s until the early 1990s. The engine is known for its reliability and durability, making it a popular choice for trucks and other heavy-duty vehicles. One of the most important components of the 6.9 IDI engine is the glow plug system. The glow plugs are responsible for igniting the fuel in the engine, and if they are not working properly, the engine may not start or may run poorly. In this article, we will discuss the wiring diagram for the glow plug system in the 6.9 IDI engine.
What is a Glow Plug?
A glow plug is a heating device that is used to preheat the air in the combustion chamber of a diesel engine. The air is compressed in the combustion chamber, and when it is heated by the glow plug, it helps ignite the fuel in the engine. Glow plugs are similar to spark plugs in gasoline engines, but they operate at much higher temperatures.
Glow plugs in the 6.9 IDI engine are typically made of ceramic and have a heating element inside. They are located in the engine block and are connected to the glow plug controller by a wiring harness.
The Glow Plug Wiring Diagram
The glow plug system in the 6.9 IDI engine is controlled by a glow plug controller. The controller is connected to the battery, the glow plugs, and the ignition switch. When the ignition switch is turned on, the glow plug controller sends power to the glow plugs to preheat them. The amount of time the glow plugs are heated depends on the temperature of the engine and the outside air.
The wiring diagram for the 6.9 IDI glow plug system is shown below:
| Wire Color | Wire Function |
|---|---|
| Red/Yellow | Battery Positive |
| Pink/Black | Glow Plug Controller Signal |
| Black/Light Blue | Glow Plug Ground |
| Green/Red | Ignition Switch Signal |
| Green/White | Wait to Start Lamp Signal |
The wiring diagram shows the five wires that connect the glow plug controller to the various components in the engine. The red/yellow wire is connected to the battery positive terminal, and the black/light blue wire is connected to the ground. The pink/black wire is the signal wire for the glow plug controller, and it is connected to the controller and the glow plugs. The green/red wire is the signal wire for the ignition switch, and the green/white wire is the signal wire for the wait to start lamp.
How to Test the Glow Plug System
If you are experiencing problems with the glow plug system in your 6.9 IDI engine, there are a few steps you can take to troubleshoot the issue. The first step is to check the glow plugs themselves. You can do this by removing them from the engine and testing them with a multimeter. Each glow plug should have a resistance reading of around 0.6 ohms. If a glow plug has a significantly higher resistance reading, it may be faulty and should be replaced.
You should also check the glow plug controller and the wiring harness for any signs of damage. If the controller or harness is damaged, it may be causing the glow plug system to malfunction. You can test the controller by disconnecting the wiring harness and using a multimeter to measure the voltage across the terminals. The voltage should be around 12 volts when the ignition switch is turned on.
If you are still experiencing problems with the glow plug system after testing the glow plugs, controller, and wiring harness, you may need to take your vehicle to a mechanic for further diagnosis and repair.
Conclusion
The glow plug system in the 6.9 IDI engine is an important component that is responsible for igniting the fuel in the engine. The system is controlled by a glow plug controller and is connected to the battery, ignition switch, and glow plugs. If you are experiencing problems with the glow plug system, you should test the glow plugs, controller, and wiring harness to determine the cause of the issue. By understanding the wiring diagram and how the system works, you can more effectively troubleshoot and repair problems with the glow plug system in your 6.9 IDI engine.
