When your car doesn’t start, you most likely have a dead battery and the fastest way to get back on the road is a quick jumpstart. This simple trick takes less than five minutes and only requires a set of jumper cables and another vehicle. If you’ve never got around to learning the particulars or the ins-and-outs of doing it safely, we’ve got you covered.
By Timothy Dahl
Any pair of jumper cables is better than not having any at all. But if you are buying new cables, look for ones that are about 5 millimetres in size and at least 5 meters in length. Beefier cables and heavy duty clamps will be more durable and provide a better connection. It’s not always possible to place vehicles right next to each other, so having longer cables will ensure the batteries can reach each other.
Making the Connection
When handling jumper cables, keep the red and black clamps from touching, ensuring your cables aren’t mishandled when setting them up. Also try to have one person at each end to make the connection and prevent the clamps from touching. If the clamps do touch when they are hot, you could cause a short in either vehicle and create some dangerous sparks.
Start by making sure the running vehicle with a good battery is parked next to the vehicle that is dead. Open the hood of each vehicle and identify where the battery is located. Many times there is a plastic hood covering the battery or the battery posts. You’ll need to remove this hood to access the posts. It’s best to have the proper tools to do this before you get into a situation like this, so take the time to get familiar with how your battery is setup.
Once you have access to the battery posts, determine which one is positive (+) and negative (-). The positive post may have a red cable attached, but it’s best to look for a plus or minus sign to determine its polarity.
Brush away any dirt or gunk from the posts because you’ll need to create as clean and solid connection as you can. First connect one end of the red clamp to the positive post on the dead battery. Then connect the matching end of the red clamp to the positive post on the functioning battery.
Next, connect the black or negative clamp to the negative terminal on the good battery. Instead of connecting the remaining negative clamp to the dead battery, find an unpainted engine bolt or piece of the vehicle’s frame and secure your clamp to that. This will ensure a safer jump situation.
Start Your Engines
Start the functioning vehicle first, then try to start the dead vehicle. If the interior lights come on and you hear the engine turn over but it won’t start, then you may have another issue. If you hear a clicking sound when you try to start the vehicle, you might have a bad starter.
Use a multimeter to test your battery voltage. It varies with vehicle types, but it should read slightly more than 12 volts when the vehicle is turned off. If your battery is in good shape, then it’s time to troubleshoot other issues.
If your vehicle fires up and your jump was successful, leave it running while you carefully disconnect the cables, making sure the clamps don’t touch. Keep your vehicle running until you’ve reached your destination, which will give it ample time to recharge so you aren’t stuck again with a drained battery.
Image credit: Charles Williams
This article was originally written for and published by Popular Mechanics USA.