Gasoline and diesel engines start differently. In a diesel engine, fuel and air are heated until they burn, generating a spark that starts the engine. When starting a diesel-powered truck, you must follow a specific process to warm up the necessary components, especially during cold weather. You should also use an engine block heater in cold weather and take other steps (such as checking the batteries frequently) to make sure the truck starts on a cold morning.
Steps
Method 1 of 3: Follow the standard startup procedure

Step 1. Make sure the parking brake is on and the truck is in park or neutral
If you have a parking brake, be sure to pull the lever up. If you have an electronic parking brake, be sure to activate the appropriate button or lever. Check the shift lever to make sure the truck is in park (for automatic transmission) or neutral (for manual transmission).
Also, you should keep your foot on the brake. These simple safety measures will help prevent the truck from wobbling or rolling unexpectedly

Step 2. Turn the key to the start position to start the heating process
Insert the key and turn it about a quarter turn forward. The key will be set to what is known as the start position. Avoid continuing to turn the key or try to start the engine yet.
Unlike the spark plugs used in gasoline engines, diesel engines rely on hot air and compression to ignite fuel. Therefore, unless the engine is already warm (from running recently or from hot weather conditions), it will need time to warm up before starting. The start position begins this process

Step 3. Check the “glow plug” indicator lit on the instrument panel
On most trucks, you will notice that the glow plug indicator lights up on the instrument panel when you turn the key to the start position. Usually this indicator looks like a pair of inverted lowercase italic letters. When you detect that this indicator is illuminated, leave the key in the start position and wait.
- Alternatively, some trucks have a text indicator on the instrument panel that indicates something like "Waiting to start." You can consult your owner's manual for specific details about your truck's gauges.
- Glow plugs are heating elements (pencil-shaped and battery-powered) that help heat air and fuel and speed up the combustion process. It may take 1 to 15 seconds or more to warm up sufficiently, depending on the engine temperature.
- Some diesel-powered trucks have an air intake heater that lights up next to the glow plug. However, this does not affect the boot process, and is rarely noticed if ever indicated by a panel light.

Step 4. Turn the key all the way to start the truck once the glow plug light goes out
In most trucks, the glow plug will be hot and the engine will be ready to start when the glow plug indicator light on the panel goes out. Once this happens, you should turn the key forward to the start position and hold it there while the engine starts. If everything is in good working order, it should start right away.
- If you have an automatic transmission, just make sure the shift lever is in the park position. If you have a manual transmission, you should press the brake with your right foot and the clutch with your left foot during startup, and make sure the gear lever is in neutral.
- If you have a "Waiting to start" text indicator light, you should wait for it to turn off. Confusingly, this could likely be replaced (or not) by a glow plug indicator that lights up to tell you it's hot and the engine is ready to start. Consult your owner's manual.
- You must be patient during cold weather. It may take at least 10-15 seconds for the glow plug to warm up. The truck is unlikely to start if you don't wait, and it can drain the batteries and spark plug prematurely.

Step 5. Stop and repeat the process if the engine starts for 30 seconds
In most cases, the truck should start within a few seconds after you turn the key to the start position. You can wait up to 30 seconds if necessary, but no longer than this. After 30 seconds, return the key to the off position and repeat the entire starting process.
If the truck won't start after 2-3 tries, you probably have a problem that needs to be fixed. Common culprits include batteries, glow plug, starter, and fuel lines. However, any other problem can also be responsible. Get in touch with a trusted and knowledgeable mechanic
Method 2 of 3: Using a Block Heater During Cold Weather

Step 1. Locate the 3-pin plug on the front of the truck
Most diesel-powered trucks feature a short power cord with a 3-pin plug on the end. It's often hidden behind the front grille, but can be found under the hood, behind the front bumper, or elsewhere. Consult your owner's manual if you need help finding it.
- The power cord is connected to a block heater under the hood. Although they take various forms, all block heaters help keep the engine warm enough that the diesel engine can start during cold weather.
- If the truck doesn't have a power cord, it probably doesn't have a block heater. Check with your dealer or a mechanic to add one, especially if you live in an area that experiences temperatures below freezing.

Step 2. Plug in the heater for 3 hours or more after 6 hours or more in freezing temperatures
Connects a heavy-duty, weather- and cold-weather-resistant 3-prong extension cord to the plug protruding from the truck. Then plug it into a standard outlet. For practical and safety reasons, try to park the truck (especially overnight) within 50 feet (15 m) of an electrical outlet.
- Avoid using a single extension cord over 100 feet (30 m) in length, and do not connect multiple extension cords.
- As a general rule of thumb, if the truck has been sitting (not running) in temperatures below 0 ° C (32 ° F) for more than 6 hours, you should connect the block heater for at least 3 hours before attempting to start it. In practical terms, this means that you should plug in the block heater overnight in cold weather.

Step 3. Start the engine as usual and then unplug the block heater
Follow your normal starting procedure, allowing the glow plug to warm up before starting the engine. When starting the engine successfully, remember to get out and unplug the extension cord.
It's not an absolute necessity to keep the block heater plugged in while starting the engine, but it does provide that little extra heat that can make all the difference on a very cold morning
Method 3 of 3: Maintain the Batteries and Fuel System

Step 1. Test the 2 batteries regularly and replace them both when necessary
Unlike gasoline passenger vehicles, diesel engine vans always have 2 batteries under the hood. This is mainly due to the power requirements of the glow plug before starting. Raise the hood and use a voltmeter or power probe to check the voltage of both batteries at least once a month. You should read the owner's manual for specific instructions on how to test the truck's batteries.
- Generally speaking, both batteries should be tested between 12, 4 and 12, 7 volts. If you get a higher voltage reading (which usually indicates a wiring problem), you should see a mechanic.
- In some cases, you can recharge dead batteries yourself, but you can professionally recharge or replace both batteries if you're not entirely sure what you're doing.
- Automotive batteries can lose half their power in extremely cold climates, so you should check even the newest batteries regularly during the winter.
- For best results, you should always replace both batteries at the same time, even if only one battery fails to hold a charge.

Step 2. Keep the tank filled with winter grade diesel fuel
By keeping the tank full, you make diesel fuel less likely to gelatinize at low temperatures. Additionally, it limits the amount of condensation inside the fuel tank and lines, which can inhibit starting. When filling the tank, you should choose a winter-grade diesel fuel, which should always be available during cold weather.
Winter grade diesel has additives that reduce the fuel's tendency to gel during cold weather. Untreated diesel fuel will begin to gelatinize at approximately -6 ° C (21 ° F)

Step 3. Replace the fuel filter according to the manufacturer's recommended schedule
As the name implies, the fuel filter traps debris and impurities that may be present inside the tank and keeps them out of the engine. An old rule of thumb used to be to replace the filter every 48,000 km (30,000 miles), but modern filters can often last much longer. Check your owner's manual to verify the recommended program.
- If the truck is slow to start (or is reluctant to start), a clogged fuel filter may be the culprit.
- You will likely be able to replace the filter on your own with the right amount of knowledge, but this task is often best left to a skilled mechanic.

Step 4. Install a starter fluid injector if it is frequently cold where you live
A professionally installed starting fluid injector helps jump-start the combustion process to keep the engine running during cold weather. Installing the injector can cost anywhere from $ 1,000 to more, but it can be a worthwhile investment if you live in a cold climate.