How to tell which car battery cable is positive

When working on your car’s battery, it’s important to know which cable is positive and which one is negative. If you make a mistake and connect the cables the wrong way, you risk damaging your car’s electrical system and possibly injuring yourself. Therefore, it’s crucial to identify the positive cable correctly.

One of the easiest ways to determine which cable is positive is by looking for the + sign on the battery terminal. Typically, the positive terminal is marked with a symbol or a letter “P.” However, in some cases, the positive terminal may have a different marking, such as a red cover or a larger diameter than the negative terminal.

Another method to identify the positive cable is to trace the cable from the battery to the starter motor. Usually, the positive cable runs directly to the starter motor, while the negative cable will be connected to the car’s frame or engine block.

In this article, we’ll provide some tips and tricks for figuring out which cable is positive to ensure that you can safely and confidently work on your car’s battery.

How to Determine Positive Car Battery Cable

1. Look for the Positive (+) Sign on the Battery

The easiest and most accurate way to determine which car battery cable is positive is to look for the positive (+) sign on the battery. The positive terminal will always have this sign and it can be located either on top or on the side of the battery.

2. Check the Color of the Battery Cables

If you can’t find the positive sign on the battery, you can check the color of the battery cables. The positive cable is usually red or has a red stripe, while the negative cable is usually black or has a black stripe.

3. Use a Multimeter or Test Light

If you are still unsure which car battery cable is positive, you can use a multimeter or a test light to determine which cable is carrying a positive charge. First, connect the black probe of the multimeter or test light to a good ground, such as the negative battery terminal or chassis. Then, touch the red probe of the multimeter or test light to each battery cable in turn. The cable that lights up the test light or gives a reading on the multimeter is the positive cable.

• Remember to wear gloves and eye protection when working with car batteries.
• Always disconnect the negative battery cable first before disconnecting the positive cable.
• When reconnecting the battery cables, connect the positive cable first before connecting the negative cable.

Step 1: Check the Insulation Color

The first step to determine which car battery cable is positive is to check the insulation color of the cables. Most manufacturers use either red or orange color for marking the positive cable while the negative cable is usually black or white.

If you cannot distinguish between the colors, then look for a plus or minus symbol on the battery terminals. The positive terminal will have a plus symbol, while the negative terminal will have a minus symbol.

• If you have an older car that does not have color-coded cables, then it is best to consult your car’s manual for identification.
• You can also check the battery itself for any markings that indicate which cable is positive or negative.

It is crucial to identify the positive and negative cables correctly as reversing their roles can cause serious damage to the car’s electrical system.

Step 2: Look for the (+) Symbol

Another way to determine which car battery cable is positive is by looking for the (+) symbol. This symbol is usually marked on the battery or on the battery cables themselves. It may be colored red or have a red plastic cover.

If the (+) symbol is visible, then the cable connected to it is the positive cable. This cable will lead to the positive terminal on the battery.

However, it’s worth noting that not all car batteries have the (+) symbol. In this case, you can use the color-coding method or consult your vehicle’s owner manual to determine which cable is positive.

• Look for the (+) symbol on the battery or cable.
• The cable connected to the (+) symbol is the positive cable.
• Not all car batteries have the (+) symbol.
• If in doubt, use the color-coding method or consult the owner’s manual.

Step 3: Inspect the Battery Posts

Look for Positive and Negative Markings

Once you have located the battery, take a closer look at the battery posts on the top of the battery. There should be markings indicating which post is positive and which is negative.

Check for Color-Coded Cables

Additionally, you might notice that the cables attached to the battery posts are color-coded. The positive cable is usually colored red and the negative cable is usually colored black.

Identify Unmarked Posts

If the posts are not marked or the cables are not color-coded, you will need to identify which post is positive and which is negative. In this case, you can use a multimeter or volt meter to test the voltage of each post and identify which one is the positive post with a higher voltage.

Double-Check for Safety

Always double-check your work before making any connections to the battery. Making a mistake and connecting the wrong cable to the wrong post can lead to serious damage to your car’s electrical system or even cause injury.