How to Jump Start a Semi

Keep on Trucking

Jump starting a semi truck has the potential to do more damage to a vehicle or be more dangerous for bystanders than jump starting a normal car, because you're dealing with a much larger battery and more electrical power. It could permanently damage your engine if proper precautions are not taken. There are two ways to jump start any vehicle: using a battery charger, or using a second vehicle. It is important to buy a quality battery charger/jumper cables with durable, strong cables and proper voltage rather than dealing with dangers that come with using poor quality accessories.

Things You'll Need

• Safety glasses
• Battery charger with proper voltage and durable cables (noted below) OR
• Jumper cables 15 to 20 feet long and a minimum of 2-gauge thickness
• Second vehicle with a battery of equal voltage (most semis are 24 volt)

Instructions

1. Put on your safety glasses or goggles.

2. Identify the starter terminals of your vehicle. If there is any dust or rust, ensure that is cleaned before connecting any cable.

3. Turn off all electrical utilities such as the radio or video player in your vehicle before you connect the cable to your vehicle. Make sure the vehicle ignition is off.

4. Connect the end of "+" (positive) of the cable to "+" (positive) terminal of semi truck's battery.

5. If using a second vehicle, attach the other "+" (positive) end of the cable, to the "+" (positive) terminal of the secondary battery. Then attach one end of "--"(negative) cable to "--"(negative) terminal of the secondary battery.

6. In the engine compartment of the semi, find a metal plate that is secure, not painted, and without rust; such as the engine manifold, compressor bracket of air conditioner, or alternator bracket. Connect the other end of the "--"(negative) cable to that metal plate of semi truck.

7. Start the battery charger, or second vehicle. Allow second vehicle or charger to run for two minutes.

8. Start the dead semi truck. It should start. If not, check the connections thoroughly and wait for two to three minutes and start semi truck again.

9. Disconnect the cables in the reverse order from which you placed them. Turn off charger or second vehicle.

10. Allow semi to run for 15-20 minutes to fully charge the battery.

Tips & Warnings

• Read owner's manual for the connection process. Some vehicles have specific steps that can be different from the steps provided here, especially the disconnection steps. Make sure you're absolutely certain which ends of the cables are positive and negative, and which battery terminals are positive and negative.

References

• Jump Starting Tips