Repair 7

Automotive battery terminal corrosion can be caused by a number of different factors. Typically, battery corrosion should be taken as a sign your battery is older and may be having issues. Corrosion can affect the way your cars battery works and is acidic enough to destroy almost anything that comes in contact with it.

Faulty Terminals

Battery corrosion can be caused by loose or improperly functioning battery terminals. If the connectors and terminals are not tight, corrosion can build when gases and other substances come in contact with the metal on the battery terminals or posts, causing chemical reactions. Dirty battery terminals will also cause corrosion, because the dirt causes the terminal connection to be looser than it would be otherwise.

Battery Gases

One of the primary causes of battery corrosion occurs when gases from inside the battery escape into the outside air where they come in contact with the battery posts and terminals, causing corrosion to build on the metal of the posts and terminals. Battery gases may escape due to loose or improperly functioning battery terminals or cracks or holes in the actual battery casing.

High Temperatures

The warmer the climate you live in, the more quickly corrosion will build on your battery. Power Battery claims that batteries kept in climates of temperatures where the battery is regularly warmer than 77 degrees Fahrenheit will corrode more rapidly than those in cooler climates.

Side post battery terminals are commonly used in GM vehicles. However, this is not to say that a top post battery and terminals cannot be converted on almost any vehicle. To remove the side post battery terminal is just as easy (if not easier) than removing the top post battery terminal clamp. Side post battery terminals employ a bolt-type terminal that secures the respective battery cable to the battery.

Instructions

1

Open the hood to the vehicle.

2

Put on the safety goggles.

3

Place a suitable sized box-end wrench or a ratchet and socket on the hex-head of the (black-wired) negative side post battery terminal (removing the negative terminal post first will minimize the occurrence of sparks flying from the battery terminal, which could result in igniting flammable hydrogen gases emitting from the battery vents). Many GMs use an 8mm or 5/16-inch wrench (although aftermarket or converted side posts terminals may take a much larger wrench or socket). Also some side post batteries, but not all, restrict using a ratchet and socket due to limited room between the terminal post and other engine components.

4

Turn the wrench (or ratchet and socket) counterclockwise. Keep in mind that if the battery terminals are facing the engine compartment, the terminal bolt will require being loosened to the right (clockwise) in order to remove.

5

Isolate the battery terminal bolt from the battery so it does not come back into contact with the battery post while removing the positive (red-wired) battery terminal side post bolt in the same fashion. Some GM vehicles come equipped with a plastic cover for the positive battery terminal post to help prevent corrosion. If equipped, unsnap the cover by hand first.

Disconnecting a vehicle power or ground cable from a battery terminal allows you to safely work on your vehicle or exchange the battery. When you examine your battery, you will find either top-mounted or side-mounted terminals. Although the connectors look different, they both come off with similar tools. Top-mounted battery terminals require an extra step. In both cases, removing the risk of shock will increase your safety when working around the battery.

Instructions

Disconnect a Top-Mount Battery Terminal

1

Loosen the nut located on the side of the battery ground post (the negative post, marked by a minus symbol) by turning it counterclockwise with an adjustable wrench.

2

Move the loosened battery terminal clamp from side to side until it starts to move without resistance.

3

Slide the end of a flat-head screwdriver under the terminal clamp. Twist the handle of the screwdriver to push the clamp away from the battery.

4

Lift the ground terminal from the battery post. Remove the positive terminal clamp from the battery using the method described.

Disconnect a Side-Mount Battery Terminal

5

Turn the ground bolt (the bolt that secures the ground cable to the battery ground terminal, marked by a minus sign) protruding from the center of the ground terminal counterclockwise with an adjustable wrench.

6

Continue turning the wrench until the terminal tilts on its side.

7

Pull the side-mounted terminal from the battery with your hand. Disconnect the positive terminal cable bolt in the same manner.