SAFETY GUIDE
How to Properly Jumpstart a Vehicle
A dead battery is one of the most common roadside problems. However, connecting jumper cables incorrectly can damage vehicles or create safety risks.
How to properly jumpstart a vehicle starts with understanding the correct cable order and safety precautions. Although jumpstarting is straightforward, mistakes can cause electrical damage or sparks.
Step 1: Position the Vehicles Safely
Park the vehicles close enough for the cables to reach, but do not let them touch. Turn both vehicles off and engage the parking brakes.
Step 2: Identify Battery Terminals
Locate the positive (+) and negative (–) terminals on both batteries. Positive terminals usually have a red cover or marking.
Step 3: Connect Cables in Order
Red clamp to dead battery positive, other red clamp to good battery positive, black clamp to good battery negative, final black clamp to unpainted metal on the dead vehicle (not the battery).
Step 4: Start the Working Vehicle
Start the vehicle with the good battery and let it run for several minutes. Then attempt to start the disabled vehicle.
Step 5: Remove Cables in Reverse Order
Once the vehicle starts, disconnect the cables in the exact reverse order. Keep clamps from touching each other during removal.
Warning: Never connect the final black clamp directly to the dead battery's negative terminal. Doing so increases the risk of sparks near battery gases.
After the Vehicle Starts
Allow the engine to run for at least 20–30 minutes to help recharge the battery. However, if the vehicle struggles again later, the battery may be failing. In that case, schedule a car battery replacement.
If you prefer professional assistance, use our jump start service or request emergency roadside assistance.
When Not to Jumpstart
- Cracked or leaking battery case
- Visible corrosion or severe damage
- Strong sulfur (rotten egg) smell
- Hybrid or EV system concerns without proper guidance
Need Roadside Help?
If your battery won't hold a jump or you'd rather leave it to the professionals, call Precision Roadside Service.