How to Jump-Start a Diesel Truck

Do you prefer a diesel vs. a gasoline truck? There are distinct advantages, including more towing power, higher torque, and an engine that could last longer than a gasoline version. One of the quirks of having a diesel truck is that they have two batteries due to the cranking amps needed to start the engine. 

We offer some diesel GMC and Chevy trucks on our lot with better towing power, versus a gasoline engine, for your Rome-area tasks or property management outside Dalton. A heavy-duty diesel truck needs some extra maintenance every once in a while in Rockmart and beyond, including paying closer attention to the diesel truck battery or two sitting next to the engine block. 

Your diesel truck battery might lose its charge at some point due to several reasons. The most likely reason is that the electrical system ran for too long without the engine running. One of the batteries might be near the end of its operational life. Whatever the reason, we’ll show you how to jump-start a diesel truck with two batteries with our guide from Welborn Chevrolet of Rome near Adairsville. We want you to get the best driving experience possible with your truck.

How to Jump-Start a Diesel Truck With Two Batteries: Supply List

Your truck has more than one diesel truck battery because it takes more cranking amps to start the engine. Fortunately, you only need to connect to one of the two batteries when learning how to jump-start a diesel truck with two batteries. 

We have a short list of supplies you’ll need to take care of this.

1. Robust jumper cables at least 10 feet long
2. A second vehicle battery to supply power to the dead battery

The second battery usually comes from another vehicle with a working battery. If you’re on a job site or at a rural property and you need a jump-start quickly, consider a portable battery jumper for your truck that you can buy at automotive supply stores. 

Another option is to call a towing service or a service center that offers mobile services. This type of service comes in handy when you don’t have another battery nearby.

How to Jump-Start a Diesel Truck With Two Batteries Properly

Now, we’ll go step by step on the proper way to jump-start a diesel truck. 

1. Have the two vehicles face each other with the batteries as close as possible. 
2. Turn off both vehicles and turn off all of the accessories in both vehicles to get the most out of the charge.
3. Set the parking brakes so that they don’t accidentally roll away. 
4. Raise the hood on both vehicles.
5. Locate the batteries. 
6. You only need to connect one of your two diesel truck batteries to make this work.
7. Find the positive and negative battery terminals. The positive terminal has a red cover while the negative terminal is usually black.
8. Get out the jumper cables. 
9. Separate the red ends from the black ends on the jumper cables.
10. Make sure the ends of the jumper cables don’t touch each other. That could create a short circuit, which could cause issues when you try to jump-start your diesel truck.
11. Connect a red clamp to the positive post on the dead battery.
12. Clip the other red clamp to the positive terminal of the working battery with the charge.
13. Connect the black clamp to the negative post on the good battery.
14. Connect the last black clamp to a grounded, unpainted metal surface on your car’s frame. Look for a metal bar or part that keeps a portion of the engine in place as the ideal piece of metal for this. The metal bar on which the alternator sits represents another good place for the second black clamp.
15. PRO TIP: It’s vitally important to connect the jumper cables in this order. Otherwise, your diesel truck won’t jump-start.
16. At this point, the electrical connections are made and there will be electricity flowing through the jumper cables. Don’t touch the clamps or the terminals. You could cause a spark. Causing a spark might drain the good battery, and then the truck won’t jump-start due to low juice from the helper’s battery.
17. Start the engine of the vehicle with a good battery. 
18. Let the vehicle with a good battery run for a bit to strengthen the battery. The alternator on the vehicle with a good battery will recharge that battery.
19. PRO TIP: Gradually press the accelerator of the vehicle with the good battery until the RPMs of the engine get to about 1,500. Idling is around 800 RPMs. The person in the good vehicle will notice a dip in the power when the vehicle with the dead battery tries to start the engine. If the vehicle with the good battery stalls, your truck won’t jump-start.
20. Try starting the engine on your diesel truck with two batteries.
21. PRO TIP: It may take some time for your diesel truck battery to recharge, so it may take a few minutes for the jump-start to work.
22. If the vehicle with the dead battery starts, allow it to keep running for several minutes. Because your diesel truck has two batteries, we recommend 20 minutes of running time.
23. Carefully remove the jumper cables in the reverse order that they were placed while keeping both vehicles running.
24. Make sure the metal clamps don’t touch each other when you remove them! This, again, could cause sparks or a short circuit.
25. Remove the black clamp from the unpainted metal surface first, then remove the other black clamp, then the red clamp on the good vehicle, then the red clamp on the vehicle that needed the jump-start.
26. Close the hood.

How to Charge a Diesel Truck With Two Batteries

You need to understand how to charge a diesel truck with two batteries to keep it running great. Your truck’s alternator can help with this, provided the alternator isn’t the one causing the problem.

1. Keep the engine running on the jump-started vehicle for at least 20 minutes. This will allow the alternator to recharge the battery for a time, and give your batteries enough juice to start the engine next time. Put your foot on the gas without driving anywhere if you need to handle some work in the truck cabin. Or, go for a short drive.
2. Drive home or to your next destination!
3. If you notice you need a jump-start again soon after, there might be another problem with your vehicle such as a bad starter or an alternator that no longer recharges the battery. Consider calling a jump-start car service or a tow truck to bring your vehicle to a service center after you see how to charge a diesel truck with two batteries.

How Long Do Diesel Truck Batteries Last?

How long diesel truck batteries last is around four years. This is just a general rule of thumb. How long your diesel truck batteries last depends on the climate, how much you drive, and the battery itself. Taking care of your truck can lengthen how long diesel truck batteries last, giving you a better driving experience. We will test the batteries every time you come in for service at Welborn Chevrolet of Rome.

Contact Welborn Chevrolet of Rome for Trusted Car Service

Does your diesel truck need service? Contact us or call (706) 509-0370, and our team will take care of the truck that takes care of you. We’re happy to help with your automotive needs at Welborn Chevrolet of Rome.