How To Jumpstart A Truck With Two Batteries

Why are there two batteries in my truck? This is one question that you will find many new drivers asking. Trucks usually have two batteries or one large one to help provide the high cranking amps needed to handle the resistance load its diesel engine requires when starting. The situation even gets worse when the truck can’t start, and jumping is required.

Many new truck owners, especially, are not sure of how to jumpstart a truck with two batteries. Remember, here we are dealing with two cells as opposed to the one we are used to when dealing with the small cars. Therefore, you must understand the connection before you proceed with the process.

When dealing with two batteries, a slight mistake can end up killing your cell. Therefore, without saying much, here is a step-by-step guide on how to jump your dual-battery truck.

10 Steps To Jump-Start Truck Batteries

1. Open the Hood

The first step towards jumping a car is opening the hood to allow access to the batteries. For the truck, finding the cells is usually easy, as opposed to the small cars. Small cars typically come with different designs, and that means the batteries are sometimes in the position you can’t expect them to be. Once the hoods are opened, support them using the metallic piece that is usually hidden on the front part of the engine.

2. Position the Donor Vehicle

Your next move should be to move the donor vehicle close to the truck. The step is to ensure that the jumper cables can access the batteries from both ends. If you’re lucky to have long wires, that should be less of your worries. However, when moving the cars, ensure that they don’t touch each other as this can lead to shorting during the process.

3. Put Off the Electronics on the Vehicle

Next, you should go ahead and switch off the electrical components on both the donor vehicle and the truck. You should also switch off the donor car before proceeding with the connection. Putting off the electronics prevents them from shorting from the charge that may be coming from the donor vehicle, for instance. Also, it’s recommended to have the two cars shift their gear to parking or neutral, and the parking brakes lifted.

4. Ensure that the Donor Battery isn’t Low

As stated earlier, most trucks usually have two batteries to provide sufficient power needed to crank their diesel engines. Therefore, one mistake you can make is trying to start the truck using a low battery. It can’t help at all. You may end up draining the donor battery, as well. Therefore, you must confirm the state of the donor battery before going ahead with the connection. If it’s low, try using a different battery or vehicle.

5. Attach the Positive Terminals

Currently, you will find various jumper cable brands in the market. Each brand usually has a unique design. Luckily, most cables typically come with colored wires for the sake of polarity. You are needed to connect the positive terminal of your donor battery to the positive terminal in one of the truck’s battery. The connection should be made using the red-labeled clamps on both ends of your jumper.

6. Connect the Negative Terminals

Once you’re sure that the positive terminals are tightly connected, your next move should be to connect the negative terminal to a metallic point within the truck. Therefore, start by attaching the black side of your jumper to the negative terminal on the negative terminal. Then, go ahead and attach the other side of the clamp on a metallic part within the dead truck.

You can choose the engine block, for example. You must remember not to attach the clamp of moving parts such as the alternator and the propeller, as this can lead to more damages to both the car and your jumper.

7. Start the Donor Car

Like you do in the small cars, once the connection is made, your next step should be to start the donor car. The idea here is to give a high power your truck may require to start to ignite. Therefore, you should go ahead and step on the gas pedal for a few minutes. Don’t be scared. As long as the car is in the parking mode, it can’t go anywhere.

8. Start the Truck

By now, the donor battery should have enough power to start the truck. Go ahead and turn on the ignition in the truck. The truck should roar and get back to life.

9. Disconnect the Wires

Now that your truck is alive, you should go ahead and disconnect the jumper. When unplugging, remember to start with the negative/black side of the cable, followed by the positive one. By doing so, you help prevent cases of shorting, which can affect with lowers the battery life. After disconnecting, close the hood on both cars.

10. Drive the Truck for About 20 Minutes

The fact that your car couldn’t start because of a flat battery means that the cell requires some charging. The best way to top up the battery is to get on the road. Cars are usually designed to have the alternator charge their cells while the vehicle is on the move.

Therefore, after jumpstarting, ensure that you drive your car for about 20 minutes before stopping. The 20-minutes ride gives your car enough charge that you may require the next time you’re starting the car. If you turn off the truck immediately, you may end up in a similar dilemma.

What if the Jumping Doesn’t Work on My Truck?

Often, the jumping process may not work for the first time. Therefore, if you find yourself in such a situation, you should first check to confirm that the donor battery has the amount of power your truck requires to ignite. If the voltage is sufficient, check the connections. You can try changing the point at which you attached the negative clamp on the truck.

Repeat the jumping three to five times. If your truck can’t start even with all these attempts, it can be an indication that new batteries are needed. But before you start shopping for a new battery, you can try topping up the battery using a charger. The tactic can save you from spending a lot of cash over a problem that could be dealt with using a charger.

Sources:
1. How to Jump-Start a Diesel-Powered Automobile – dummies
2. JUMP STARTING A DUAL BATTERY DIESEL ENGINES ONLY Repair Guide – AutoZone