When you’ll need to jump start your car
If you car won’t start (it makes a pathetic “clearing its throat” noise or just whirs and clicks a little when you turn the ignition), you probably need a jumpstart to get you back on the road.
Things you’ve done that might have gotten you here:
- You left your headlights on
- You left the goddamn dome light on
- You left your car parked for like a month
If you battery is flat for some other reason (bad alternator, old battery), you’ll want to get your car checked out soon.
Before you jump start
- You need jumper cables. It’s a good idea to buy a set and keep it in your car (inside the spare wheel well is a good place). The thicker the better (smaller gauge means thicker wire). Something like these or these are good.
- If either car has an electronic ignition system or is a hybrid car, jumpstarting can damage it, or a different procedure might be required – check the manual or Google your specific model.
- It’s almost impossible to electrocute yourself while jumpstarting a car. What’s more likely is damaging your car if you connect the clamps in the wrong order, or causing a spark if you connect it to the wrong thing. Which is what this guide will help you avoid!
How to jump start your car
1. Park the cars nose to nose (close but not touching), turn them off and open both hoods.
- Make sure the battery voltages match.
- If either battery is cracked, damaged, leaking or frozen (remove the caps and check if it’s cold), it is not safe to jumpstart – you’ll need to get a new battery. Call a tow truck. (By “not safe”, we mean the battery can explode…car batteries contain concentrated sulfuric acid, so don’t cheap out here.)
- Turn off any power-using things (lights, music) in the dead car to give your car the best chance of starting.
2. Attach the clips.
Here’s the order:
- Red clip to positive terminal of dead battery
- Other red clip to positive terminal of donor battery
- Black clip to negative terminal of donor battery
- Other black clip to exposed, unpainted metal surface under the hood of the dead car not too close to the battery (ideally a screw on the engine block, but the strut holding the hood open will do). This reduces the chance of sparking compared to attaching the clamp to the negative terminal.
The positive terminal will be red, have “POS” or “+” on it, or be bigger.
If the terminals don’t look too clean, clamp hard and rotate the clips a bit to get better contact.
Handle the clamps by the insulation, and ensure they don’t touch each other or any other metal in the car.
To prevent the clips from flopping around when you’re clamping, you can clip them onto the plastic on their own cable.
Make sure the cables aren’t in the way of any moving parts before you move onto the next step.
3. Start the donor car and let the engine run for a few minutes.
This charges the dead battery a bit without draining the good battery.
4. Try to start the dead car.
If it won’t start, check that everything is properly connected, then wait a few more minutes and try again. You can also rev the engine of the donor car to help charge the dead battery.
5. Once the car starts, disconnect the cables in the reverse order.
That is: black on no-longer-dead car, black on donor car, red on donor car, red on no-longer-dead car.
Don’t turn off the engine at this point! Drive around for 15-30 min with minimal stopping to build up a charge in the battery so the car will start again after you turn it off.
And go home and tape that dome light switch to “auto”…