To jump-start a car, connect positive to positive, connect the donor battery's negative terminal, then connect the final negative clamp to a solid unpainted metal ground on the disabled vehicle.
Start the donor vehicle, let it run briefly, then try starting the disabled vehicle. Once it starts, disconnect the cables in reverse order. Always follow the owner's manual because some vehicles use designated jump points or have special procedures.
If you are unsure about the battery condition, the correct connection points or whether the vehicle can be safely jump-started, use roadside assistance instead.
Make sure the vehicles and battery are safe to work around.
| Check | What to Do | Why It Matters |
|---|---|---|
| Owner's manual | Confirm jump-starting is allowed and locate the approved jump points | Some vehicles use remote terminals or have special procedures. |
| Battery condition | Do not proceed if the battery is cracked, leaking, swollen or frozen | Damaged batteries can be dangerous. |
| Vehicle position | Park close enough for the cables to reach without the vehicles touching | Keeps the process controlled and prevents cable strain. |
| Ignition / accessories | Turn both vehicles off and switch off lights, climate control and accessories | Reduces electrical load while connecting cables. |
| Transmission / parking brake | Place both vehicles in Park or Neutral as appropriate and set parking brakes | Prevents vehicle movement. |
| Cables | Use jumper cables in good condition with clean clamps | Damaged or corroded cables can make poor connections. |
Connect the jumper cables in this order.
Connect red to the dead battery positive terminal
Attach one red clamp to the positive (+) terminal or the vehicle's designated positive jump point.
Connect red to the donor battery positive terminal
Attach the other red clamp to the donor battery's positive (+) terminal.
Connect black to the donor battery negative terminal
Attach one black clamp to the donor battery's negative (-) terminal.
Connect the final black clamp to a ground point
Attach the last black clamp to a solid, unpainted metal grounding point on the disabled vehicle, away from the battery when the owner's manual instructs.
Also keep loose clothing, cables and hands away from belts, fans and other moving engine components.
Once the cables are connected correctly, start the donor vehicle first.
- Double-check all four cable connections
- Start the donor vehicle
- Let it run for a few minutes
- Try starting the disabled vehicle
- If it does not start, wait a little longer and try again
- Do not crank the starter continuously for long periods
- If the vehicle still will not start after a few reasonable attempts, stop and diagnose the problem
- Do not assume every no-start is caused by the battery
The battery may be too discharged, the cable connection may be poor, or the problem may involve the starter, alternator, battery terminals or another electrical fault.
Remove the jumper cables in the reverse order.
Remove the ground clamp from the restarted vehicle
Disconnect the black clamp from the metal ground point first.
Remove black from the donor battery
Disconnect the black clamp from the donor battery's negative terminal.
Remove red from the donor battery
Disconnect the red clamp from the donor battery's positive terminal.
Remove red from the restarted vehicle
Remove the final red clamp from the restarted vehicle's positive terminal or jump point.
A successful jump-start does not automatically mean the battery is healthy.
Let the vehicle run and follow the manufacturer's guidance. If the battery was simply discharged, the charging system may restore some charge while the engine runs, but a severely depleted or failing battery may not recover properly from driving alone.
If the vehicle dies again shortly after the jump, repeatedly needs jump-starts or shows a battery/charging warning light, have the battery and charging system tested. The cause may be an aging battery, alternator problem, poor connection or parasitic electrical draw.
There are situations where roadside assistance is the safer choice.
Cracked, leaking, swollen or frozen
Do not attempt a conventional jump-start on a visibly damaged or frozen battery.
You cannot identify the approved terminals
Use the owner's manual or professional assistance instead of guessing.
Special procedures may apply
Many hybrids and EVs have a 12-volt battery, but procedures vary. Never use high-voltage components as jump points.
Jump-starting does not solve it
If the vehicle repeatedly will not start, the real issue may be the battery, alternator, starter or another electrical system fault.
If your car needed a jump, find out why before it leaves you stranded again.
Joe's Auto Repair can test the battery, charging system and starting system to determine whether the issue is a weak battery, alternator problem, starter concern, poor connection or another electrical fault.
Needed a jump-start recently?
Joe's Auto Repair serves drivers from 101 University Blvd W in Silver Spring, MD 20901 near Four Corners. If your car needed a jump, cranks slowly or keeps dying, our team can test the battery, alternator and starting system before the next no-start catches you off guard.
Schedule Battery Testing →Jump-starting questions.
Connect red to the disabled vehicle's positive terminal, red to the donor battery's positive terminal, black to the donor battery's negative terminal, then the final black clamp to the approved ground point on the disabled vehicle.
Many manufacturers direct the final negative connection to a designated ground point away from the battery. This helps keep the final connection away from the battery itself. Follow the vehicle owner's manual for the exact location.
A few minutes is often enough to provide some charge to the disabled battery, but the correct procedure can vary. Avoid repeated long cranking attempts if the vehicle will not start.
Incorrect polarity, poor connections or ignoring the manufacturer's procedure can damage electrical components. Always identify positive and negative terminals carefully before connecting cables.
Many hybrids and EVs use a conventional 12-volt battery, but jump-start procedures vary significantly. Follow the owner's manual and never connect jumper cables to high-voltage battery components.
The problem may involve a severely discharged or failed battery, poor cable connections, the starter, alternator or another electrical or engine fault. Further diagnosis is needed.
Not automatically. Have the battery and charging system tested. The battery may simply have been discharged, or it may be weak, aging or unable to hold a charge.
Joe's Auto Repair provides battery, alternator and starting-system diagnostics at 101 University Blvd W in Silver Spring, Maryland 20901 near Four Corners.