Pre-Glow Systems Tips, Quick Tests and Upgrades

Feb 21, 2019


Welcome to Grafco Electric's comprehensive guide on pre-glow systems for all diesel engines manufactured between 1960 and 1993. Whether you are a diesel engine enthusiast or a professional mechanic, this page is your ultimate resource for optimizing and upgrading your engine's pre-glow system.

What is a Pre-Glow System?

A pre-glow system, also known as a glow plug system, is an essential component of a diesel engine. It aids in starting the engine by preheating the combustion chambers to ensure efficient and successful ignition. This system is especially crucial in colder climates or during cold engine starts.

Tips for Pre-Glow System Maintenance

Maintaining your pre-glow system is crucial for the overall performance and reliability of your diesel engine. Here are some useful tips to ensure the optimal functioning of your pre-glow system:

  1. Regular Inspection: Regularly inspect the condition of the glow plugs, their connectors, and wiring. Look out for any signs of damage, wear, or corrosion. Replace any faulty components promptly.
  2. Cleanliness: Keep the pre-glow system clean from dirt, debris, and oil. Any contamination can hinder the performance of the glow plugs and affect the starting process.
  3. Pre-Heating Time: Allow sufficient pre-heating time before attempting to start the engine, especially in colder temperatures. This ensures that the combustion chambers reach the optimum temperature for successful ignition.
  4. Quality Glow Plugs: Always opt for high-quality glow plugs from reputable manufacturers. Inferior quality plugs may not provide sufficient heat or have a shorter lifespan, leading to poor engine performance.

Quick Tests for Pre-Glow System

Performing quick tests can help identify potential issues with your pre-glow system. Here are some simple tests you can conduct:

  • Visual Inspection: Check for visible damage or signs of wear on the glow plugs, connectors, and wiring.
  • Resistance Test: Using a multimeter, measure the resistance of each glow plug. Compare the readings to the manufacturer's specifications to ensure they are within the recommended range.
  • Current Draw Test: Measure the current draw of the glow plugs during the pre-heating phase. Any significant deviations from the expected value may indicate a faulty plug or wiring issue.
  • Relay Test: Check the functionality of the pre-glow system relay. Faulty relays can prevent the glow plugs from receiving power, leading to starting issues.

Upgrades for Enhanced Pre-Glow Performance

If you are looking to maximize the efficiency and performance of your pre-glow system, consider the following upgrades:

1. High-Performance Glow Plugs

Upgrade to high-performance glow plugs designed to provide better heat transfer, faster pre-heating, and increased durability. These advanced plugs are often equipped with superior materials and innovative technologies.

2. Advanced Controller Modules

Upgrade the controller module of your pre-glow system to a more advanced unit. These modules offer enhanced control over the pre-glow process, allowing precise heating cycles, improved heat distribution, and optimized engine starting conditions.

3. Ceramic Glow Plug Technology

Consider utilizing ceramic glow plugs, which offer higher temperature capabilities and extended service life. These plugs provide superior electrical insulation, faster heat-up times, and are more resistant to extreme temperatures and vibrations.


In conclusion, maintaining a healthy pre-glow system is vital for the proper functioning of your diesel engine. Grafco Electric provides invaluable insights, tips, and upgrades to ensure optimal performance and reliability. By following our recommendations, you can enhance your engine's starting capabilities and prolong its lifespan. Trust Grafco Electric for all your diesel engine pre-glow system needs.

Roberta McLaughlin
Impressive guide on pre-glow systems for diesel engines! 🚀 Super helpful for enthusiasts and mechanics. 💪🔧
Oct 4, 2023