How to Tighten a Car Battery Terminal

A corroded car battery terminal close-up.
What You'll Need
Electrical tape
Terminal cleaner
Wire brush
Clean rags
Wrench (correct size)
What You'll Need
Electrical tape
Terminal cleaner
Wire brush
Clean rags
Wrench (correct size)

The car battery is one of the most important parts of a vehicle's operating system. If it seems to be failing, however, it doesn't always mean the battery itself it dead. Sometimes the cables or terminals can come loose, and once they do, the charge will not go where it is needed. Tightening the leads on the car battery is an easy job and the article that follows will show you how.

Step 1 - Check Placement and Coverage

It's always a good idea to check for the simplest solutions first, so open the hood of your car to look at the battery cables and make sure they're on the correct terminals.

If the connectors have been moved or placed incorrectly, then the car battery will not work the way that it should. This can also cause damage to some components in the future, so switch the cables if necessary.

The cables attached to the leads on the car battery must be insulated as well to prevent any possibility of shorting out. The wires can corrode and cause the energy created from the battery to disperse, creating a weaker connection. Cover the wires with electrical tape or replace them completely if they are not insulated.

Step 2 - Clean

Even if the car battery is properly connected, the terminals can still be too dirty for a charge to be produced or disbursed. Apply cleaner to the terminals on the car battery as well as the clamps.

Use as much as you think you need; it will not hurt the terminals or anything around them. Use a wire brush to work it in to the parts, and then wipe it off with a clean towel. Repeat this until the battery is clean.

Step 3 - Tighten the Car Battery Terminals

If you had to replace a car battery, or were cleaning other parts of the engine, you would have disconnected the car battery for safety reasons. This can cause them to become loose, but they can also loosen during normal use. However, as mentioned previously, car battery terminals are easy to tighten regardless of the situation.

Use a open end wrench to turn the bolts on the clamps counterclockwise to open them. Then, place each clamp over each of the terminals on the car battery. Make sure the negative clamp is on the negative terminal, and the positive one is over the positive terminal.

Once they are in place, you can tighten them again with the wrench. Turn it clockwise until it no longer moves.