Jump-starting a car is simple once you know the order to connect the cables in, but doing it wrong can damage the electrical system on either vehicle or, in rare cases, cause a battery to vent gas near an open spark. Follow these steps in order, and don't skip the last connection point.
Position the Vehicles and Turn Everything Off
Park the working vehicle close enough for the cables to reach without the cars touching. Put both in park (or neutral with the parking brake on for manual transmissions), turn off the ignition on both, and switch off accessories like headlights and the radio.
Connect Red to Positive, Both Batteries
Clip one red clamp to the dead battery's positive (+) terminal, then clip the other red clamp to the donor battery's positive (+) terminal.
Connect Black to Negative — Donor Battery Only
Clip one black clamp to the donor battery's negative (−) terminal.
Ground the Last Clamp — Not on the Dead Battery
Clip the final black clamp to an unpainted metal surface on the dead car's engine block or frame — a bolt head works well — rather than the dead battery's negative terminal. This keeps any spark away from the battery itself.
Start the Donor Vehicle, Then the Dead One
Let the working vehicle run for a couple of minutes, then try starting the dead vehicle. If it doesn't catch, give it a few more minutes of charging before trying again.
Remove the Cables in Reverse Order
Once the dead vehicle is running, remove the cables in the reverse order you connected them: ground clamp first, then donor negative, then both positives. Let the jumped vehicle run or drive for a while to recharge the battery.
When It's More Than Just the Battery
If a battery needs jump-starting more than once in a short period, or dies again after a drive that should have recharged it, the battery itself may be worn out — or the alternator may not be charging it properly while the engine runs. A slow crank, dimming headlights at idle, or a battery warning light are all worth having tested rather than jumping it again and hoping.
Jump-Starts and Battery Testing for Albuquerque's North Valley
We're at 4201 4th St NW in the North Valley, serving drivers from Los Duranes, Griegos, Wells Park, and the Sawmill District, as well as Rio Rancho and Corrales. See our full electrical & starting repair services for battery, starter, and alternator testing.
Frequently Asked Questions
Which cable do I connect first? Red to the dead battery's positive terminal, then red to the donor's positive, then black to the donor's negative, then black to unpainted metal on the dead car — never the dead battery's negative terminal.
Why not connect the last clamp to the dead battery itself? A weak battery can vent small amounts of hydrogen gas, so grounding the final clamp on a bolt away from the battery keeps any spark clear of it.