How to Repair a Car Battery Terminal Clamp

Corrosion on battery terminal clamps may keep your car from starting.

Battery terminal clamps hold the battery tightly so that it can effectively transfer electrical energy to your car. If a terminal clamp has a layer of corrosion on it, the amount of energy transferred to the car's components will be diminished. This can result in the battery not allowing the car to start. Cleaning and lubricating the terminal clamp will produce good contact with the battery terminal for optimal energy transfer to the car.

Things You'll Need

• Adjustable wrench
• Flat head screwdriver
• Battery terminal brush
• Cotton swab
• Petroleum jelly

Instructions

1. Open the hood of your car. Place an adjustable wrench onto the terminal's clamp bolt. Turn the bolt counterclockwise to loosen the terminal. Pull the terminal straight off the battery. If the terminal will not pull up easily, insert a flat head screwdriver under the clamp and pry it up by pressing down on the battery with the handle of a screwdriver.

2. Unscrew a battery terminal brush counterclockwise and pull the two pieces apart. One half has a pointed metal brush, and the other half is a metal brush with a hole in the center. Place the half with the hole in the center on the battery terminal. Press down and turn the brush side to side to clean the terminal. Place the pointed tip of the brush into the terminal clamp and twist it side to side to clean the inside of the clamp. When the terminal and clamp are clean, they will be very shiny and have many tiny scratches on them.

3. Hold the terminal clamp in one hand and tighten the bolt clockwise with an adjustable wrench as far as it will go. This action draws the two sides of the clamp together and tightens the clamp.

4. Turn the terminal clamp bolt counterclockwise to loosen it and place it on the battery terminal.

5. Dip a cotton swab into petroleum jelly and wipe it on the outside of the battery terminal and the inside of the clamp.

6. Replace the clamp onto the terminal and tighten the bolt clockwise with the adjustable wrench.

Tips & Warnings

• Petroleum jelly helps to make a good connection on battery terminals and prevents corrosion from forming.

• Do not touch any other metal in the car when loosening or tightening a terminal clamp. This action can create a shock hazard.

References

• Handy Manly Ness: Removing and Installing a Car Battery to Replace or Clean it