How to Change Cable Clamps on a Car Battery

Car battery cable clamps can become worn and/or corroded, which can affect the amount of charge the battery takes in and the amount of amps it puts out. Keeping the clamps clean and free from corrosion is important. If the clamps are aged, severely corroded or worn from frequent battery removal procedures, replace the clamps and follow a regular maintenance schedule to prevent corrosion from reforming.

Things You'll Need

• Safety glasses
• Battery terminal cleaner tool
• Wrench set
• Battery terminal protector spray
• Cutting dikes (optional)
• Channel locks

Instructions

1. Put on safety glasses and loosen the nut on the negative battery terminal clamp. Wiggle the clamp free of the battery post using a set of channel locks. Repeat this step for the positive cable clamp.

2. Remove the two bolts from the clamp attached directly to the cable with a wrench. Remove the cable clamp.

3. Inspect the end of the cable. If it's corroded or frayed severely, trim the cable back a little to a clean the area and cut the bad part away with the cutting dikes. Be sure not to cut too much off so that you have enough cable to properly place the clamp back onto the battery post.

4. Clean the battery post with the battery terminal tool. Be sure the area of the post is scraped clean and all corrosion is removed.

5. Install the new negative battery cable clamp and tighten the two bolts to the clamp attached to the cable.

6. Repeat the process for the positive cable clamp.

7. Place the positive clamp on the battery post first and tighten the clamp. Place the negative clamp on the battery post last and tighten the clamp. Spray battery terminal protector on the surface of the new clamps and exposed portion of the cables.

Tips & Warnings

• If replacing an "O" clamp (one that wraps completely around the battery post), you can cut the cable right behind the clamp, but again make sure you have enough cable left to properly attach to the battery. For side post batteries (often used on GM models), having to replace terminal ends is rare, but you can remove the boot and spread the crimped end of the clamp to reinstall and re-crimp a new one.

• Be sure to remove the negative terminal first, then the positive. When replacing the clamps, install the positive first and then the negative. This will decrease sparking from occurring that can ignite the fumes present from the internal gases of the battery.