Diesel Engine Electrical System and Components

Diesel engines are durable and fuel-efficient systems. They use electrical starting system to heat up the engine and initiate the fuel ignition process. Knowing the function of each part, using cold-temperature starting products, and regularly maintaining the electrical starting system can drastically improve the service life of a diesel engine.

Diesel Engine Electrical Starting Systems

While diesel engines use diesel as their primary fuel for generating mechanical force, they need electrical energy to get started. A diesel’s starting system needs to generate enough energy for two purposes:

  1. Warming the combustion chambers with the system’s glow plugs
  2. Igniting the fuel in the cylinders through a combination of heat and compression

This requires more electricity than standard gasoline engine starting systems, especially in low temperatures. Some diesel systems use two batteries, while others have a larger single battery.

Heavy-duty Electrical Systems

Central Diesel carries heavy-duty electrical systems and parts that can be used for light and heavy duty trucks, ground support equipment, construction vehicles, buses, railroad, military and more. We carry a full line of Cole Hersee heavy-duty products, which are built to withstand the forces of hauling oversized and industrial vehicles.

These heavy-duty products include:

  • Batteries and related products
  • Fasteners
  • Ignition and key switches
  • Modules
  • Monitoring devices
  • Solenoids and relays
  • Switches
  • Vehicle connectors

These products are very durable and can handle thousands of miles in extreme conditions. Many of the assemblies can tolerate temperatures as low as -70°F.

Cole Hersee Heavy Duty Catalog (PDF – 7.22MB)

Keeping Diesel Engines Warm: Cold Weather Starting Products

During startup, diesel engines require significant heat energy to enable the glow plugs and start the fuel ignition process. The energy demand increases when the diesel engines are in low-temperature conditions. In order to avoid wearing out diesel engines or causing excessive start-up strain and or damage, diesel engines can use cold weather starting products that heat up the starting system. These products include:

  • Block heaters, which heat up engines and can be used to heat truck cabins.
  • Oil pan heaters, fuel warmers, and battery warmers that provide controlled levels of heat to specific components in and near the engine.
  • Thermostats, which can monitor the engine’s temperature and engage the block heater in cycles to keep the engine within a safe temperature range.

Diesel engines offer better fuel economy than gasoline alternatives and have fewer maintenance demands. Using cold weather starting products can keep the engines in good repair.

Zerostart Cold Weather Starting Products (PDF – 4.06MB)

Diesel Engine Electrical Components

Diesel engines have electrical components to provide startup energy. Key electrical components include:

  • Alternators convert some of the engine’s mechanical energy into electrical energy to charge the system’s battery. The battery is used during startup to power the cranking motor.
  • The starter relay energizes the starter solenoid to turn the engine over and uses electrical energy stored in the battery.
  • Starters are small electrical motors that crank the engine by converting stored electrical energy into mechanical energy.
  • The solenoid is in a diesel engine’s starting motor. It moves the drive pinion during the starting process.

Starting systems are primarily made up of the alternator, battery, and starting motor, which all play an essential role in getting a diesel engine started.

Common Symptoms and Causes

Sometimes, these components can fail or stop performing as well as they used to. It’s important to know which parts cause which symptoms so you can troubleshoot a poorly performing starting system. Some of the most common problems include:

  • Batteries that don’t hold a charge. This is often to due corroded cables, dirty connections, or worn belts and pulleys.
  • An alternator that won’t charge. This problem is also caused by corrosion, dirt, and worn parts.
  • Poor starter operation. Poor performance indicates a complete failure of the battery, a solenoid that’s burned out, or a broken ignition switch. If your starter works but is sluggish, that can indicate loose connections and developing corrosion, as well as a discharged (but not dead) battery.

Diesel engines have simple starting systems, which make them easier to troubleshoot and repair than gasoline engines. Regular preventative maintenance and cleaning can help to avoid many common malfunctions.

Maintaining Your Vehicle Electrical System

To keep a diesel engine’s electrical system in good repair, it’s important to create a routine schedule for inspections and cleaning. Regularly inspecting the battery cables, plugs, and wires can help operators catch problems before they develop. It’s also important to make sure the vehicle’s lights are turned off to avoid excessive wear and battery discharge when the vehicle isn’t in use.

Quality Diesel Engine Electrical Components at Central Diesel

Central Diesel, Inc. is an engine parts distributor that offers a full line of repair, rebuilding, and installation services. We provide parts and services for diesel engines across every industry.

Contact us today or request a quote to learn more about our available diesel products.