How to Clean Electrical Connectors
Cleaning Electrical Connectors
Eventually, many electrical connections will need cleaning, particularly if they are not used frequently. The charger connection in your phone will probably remain clean for a long time simply because it is used every day, but others are so seldom disconnected that dirt and corrosion can build until good contact is no longer possible.
Chief among these are the connections on automobiles, both battery and other electrical connectors such as a plug for trailer lights. Exposure to the elements coupled with a lack of use almost guarantees that problems will arise, and they do.
Electrical connectors in the home are usually easily cleaned with a simple spray of contact cleaner, available at any electronics store such as Radio Shack, but truly dirty or corroded connections on your car are another matter. This hub, then, will describe how to clean those connections that are beyond being helped by electronic contact cleaner, particularly those on a car.
It should be mentioned that it is not a good idea to try to clean the connections on a household outlet; simply replace the outlet rather than trying to clean it. Home light switches are the same; simply replace the light switch rather than try to clean it. The reason in both cases is the same - poor electrical connections in the wiring of your home cause electrical fires and however low that risk, saving a couple of dollars isn't worth it.
How to Clean Battery Terminals
Chief among the culprits are the battery terminals on the car. Side terminals (the battery cable is bolted to the side of the battery rather than a post on the top) used on many cars today have helped somewhat but both side and top terminals can and do corrode badly. This is not normally the result of ordinary dirt or grease, but corrosion from the result of acidic vapors from the battery It's going to take a little more than rinsing them off to clean these special connectors.
A note of caution here - that white stuff in the photo to the right is the result of acid vapors from the battery. It is not violently acidic like pure battery acid, but it is acidic and sensitive skin or clothing can be burned by prolonged contact. Rubber gloves are a wise precaution and immediately rinse thoroughly any clothing that comes in contact with it. The natural reaction to getting some on your hands will be to wipe your hands on your pants, forget about it and wash those pants a day later, whereupon you will have holey pants. Don't wipe your hands on your clothing.
Remove the Connector from the Battery
Using appropriate wrenches (never simple pliers) remove the batter terminal from the battery, taking care not to get the white powder on you, your clothing or your car. Using a paper towel or preferably a disposable rag, wipe most of the corrosion off the terminal. Dispose of the towel or rag immediately Leaving it sit around while you work is a good way to get acid on your clothes or car finish.
Likewise, be very careful where tools used are set down, and make sure to thoroughly wash them in soap and water when you are finished with them.
Cleaning the battery connection
Fill a small bowl about half full of warm water and add baking soda to the point that it is completely saturated and will no longer dissolve any more of the baking soda. There should be a teaspoon or more of the baking soda left undissolved in the bowl.
Put the battery terminal, wire and all, into the bowl and gently swirl it. As the dissolved baking soda is used up in the chemical reaction going on, more will dissolve to replace it. If necessary replace the water and soda with more as it becomes too dirty or if there was insufficient soda to clean the terminal. Wipe the terminal dry and use a wire brush to shine it up, removing the very last corrosion. Special battery terminal wire brushes are available for top post batteries; side post connections can be cleaned by an ordinary wire brush.
Preventive measures are available to stop future corrosion and are recommended when cleaning or replacing any battery terminal. A spray is available that is quite effective, as are small chemical impregnated felt pads that fit over the post or under side terminals. Either one will go a long way to preventing future problems.
Re-install the terminal on the battery. Most cars will lose radio settings and such when the battery is disconnected, and some will require a few short trips before running at peak efficiency as the computer re-learns what it lost when all power was disconnected. Do not be alarmed at such short term symptoms.
Cleaning a Battery TerminalClick thumbnail to view full-size
Cleaning Other Connectors
Other connectors on the car might include spade or ring terminals and plug and socket connections. A common problem is the ring terminal where the battery wire connects to the starter, and trailer light plugs sometimes get dirty as well.
Cleaning Flat Connectors
Spade and ring terminals seldom see the corrosion of a battery terminal and are easier (and safer) to clean. If they are greasy (as opposed to simple dirt) the grease needs removed; rubbing alcohol will often help here, but so will soap and water. If water is used, however, make sure it is completely dry before re-installing the connector. In all cases, the connector must be removed from the connection to clean it.
After cleaning off simple dirt and/or grease, a small piece of sandpaper, 100 or 150 grit, is invaluable. Sand the connector until it is shiny. In many cases a ring terminal will fit over a bolt and be held in place by a nut; the nut can be sanded but the bolt it fits over is better cleaned with a wire brush.
Cleaning a Ring Terminal ConnectionClick thumbnail to view full-size
Cleaning Plug and Socket Electrical Connectors
These connections include the trailer plug and are usually simply dirty; it may be months during the winter before the camp trailer is hooked up again and during that time the socket on the car is collecting dust and road grime.
While the plug is easily washed and may benefit from a small piece of sandpaper, the socket it fits into is another story. A very small brush is very handy but a brush that small is not easy to find. A second choice is to wash it with a stream of high pressure water, but make sure it is completely dry before plugging it in. If this is a consistent problem, brushes are a superior choice.
Questions & Answers
How do I clean a small heater plug with slight corrosion?
Sandpaper or a wire brush usually works well. Steel wool can be useful as well, but care must be taken to make sure there aren't tiny strings of wool left after cleaning that could create a short between the plugs.
© 2012 Dan Harmon