Need Help Jump Starting a Car?
You turn the key in the ignition and — click. click. click. You have a dead car battery. Why does this always happen when you’re in a hurry to get somewhere?
Frantically, you dig around in your trunk and pull out some tangled jumper cables, then pop the hood. That’s when you freeze. Is red positive, black negative? Or the other way around? Aren’t you supposed to ground it somehow? Are you going to get zapped?
OK, deep breath. Here are 4 simple steps that will show you how to jump a car — safely:
- Find jumper cables.
- Find a car with a working battery.
- Connect the jumper cables.
- Start your engines.
Read more about these steps to learn the important things you need to know like:
- The importance of jumper cable order to reduce damage to you and your car.
- Which jumper cable goes to positive and negative? Black or Red?
Find your jumper cables.
Jumper cables — those red and black cords with attached copper clamps — don’t have to be fancy, but they should be the correct type for your car. They come in different gauges, from 4 to 10, and bigger is not actually better. The lower the gauge, the more power flows through. So 10-gauge cables are pretty useless, while 4-gauge cables can effectively jump-start anything. Longer cables allow you to get a jump even from a vehicle parked 20 feet away. Look for sturdy-feeling cables with solid, rubber-handled clamps. If you’re using old cables, make sure they’re not frayed or corroded. If they are, then buy some new ones. We want to avoid electrical shock when jumping a car!
Find a car with a working battery.
If you’re at home and there’s another car parked next to yours in the driveway, you’re in luck. If that’s not the case, try to find a neighbor or a friend who can pull up next to you. Or, call AAA or another roadside assistance service. Make sure the jumper cables can reach from the other vehicle to your dead car battery, and put on the emergency brakes. Pop both hoods.
It’s possible to jump start a car without another car, but you’ll need a battery designed for the job. Emergency jump starters cost around $40 to $75, and some charge your cell phone as well.
Connect the jumper cables properly.
Take off the plastic covers on both batteries, if they have them. See the little nubs that stick out? Those are the terminals. The positive one should have a “+” sign, the negative one a “–” sign. The key to jumping a car battery is this: Red = positive, black = negative. If they’re dirty or corroded, wipe them off as best you can.
While you’re jumping your car, don’t let the cables’ metal clamps touch each other. First, connect one of the red clamps to the positive terminal on the dead battery. Connect the other red clamp to the positive terminal of the good battery. Connect the black clamp to the negative terminal on the good battery, and then ground the other black clamp by attaching it to an unpainted portion of the frame or the engine on the car that’s getting jumped. This speeds up the charging process.
Connecting the positive terminal of one battery to the negative terminal of the other is like crossing the beams in “Ghostbusters” — bad things happen! The resulting electrical surge will cause the battery to heat up, generate hydrogen gas and even explode. “The heat can melt internal and external battery parts, while the pressure from the hydrogen gas can crack the battery casing,” says ItStillRuns. The surge of current can heat up your cables, even melting them, and can also fry your car’s electronics. This is why the jumper cable order is important!
The good news is that it’s hard to electrocute yourself with a 12-volt car battery. The human body has enough resistance that simply touching the terminals will produce just a mild tingle, at most.
Start up your car.
First, start the car with the good battery. Then, try starting your car again. It should come back to life. Leave the engine running while you disconnect the jumper cables (in reverse order); it’ll need time to fully recharge the battery.
If the car won’t start, recheck all your cable connections and try again. Still nothing? You may have a bad starter or fuel pump. Or could your car be out of gas? If you continue to have problems starting your car, or if your battery goes dead again, get it checked by your mechanic.