How To Clean Trailer Plug: Best 5 Solutions

Keeping your trailer and RV plug exposed can cause a dirty and corroded connector. This could leave you with a bad connection and cause things to light your brakes and the trailer lights to not work.

So how do you clean a trailer plug? Here are 5 solutions on how to clean a trailer plug and make sure you have good electrical contact:

  1. Contact Cleaner
  2. Wire brush
  3. WD-40
  4. Pipe Cleaner
  5. Vinegar and Water

In this post, we will review each of these solutions with the advantage and disadvantages of each method.

Table of Contents

Contact Cleaner

Using contact cleaners can help you keep it clean and free from dirt or foreign particles that could interfere with its performance. Contact cleaner removes any grime or oil buildup on the surface, which can cause corrosion over time. It also helps improve electrical connections so that everything works as it should.

Contact cleaner is great for mildly corroded plug

Spray in the plug using the straw provided with the can. You can get the plastic and metal connectors very wet, as this solution will flash and evaporate quickly. Allow drying a minute before reconnecting with the RV or trailer.


The advantage of this method is that it is quick and straightforward. There is no brushing, just give it a spray and let the solvents do their work. It also has an advantage because it is a liquid and can get into tight spaces. This solvent will get into every crevice and clean your plug in the impossible-to-reach locations.


The first disadvantage is that you may not have this can of cleaner lying around. You must go to a home center or auto store to pick it up. But once you have, leave it in your truck, and you will have it for next time, especially if you are on the road and need to give the plug a quick spray to keep it clean.

The second disadvantage is that the solvent can only clean so much. The solvent will get most of the surface dirt off if you have a mildly corroded plug. But a real deep clean will need more elbow grease and brushing. Which now will bring us to solution number two.

Wire Brush

Always use the slightest pressure and force when using a wire brush cleaning. Start light and see how that cleans your connector. If the light pressure doesn’t work, explore using heavier pressure as you clean the trailer plug.

A wire brush also works great on your ground wire. If you have your wire brush out now, it’s a good time to glance around your trailer and see if there is any corrosion on that white wire.

For more info on the ground wire, check out How to Check You Ground Wiring post.


The most significant advantage is that it will get the most cleaning done. For extremely dirty and corroded plugs, this is the best option to get you back down to the shiny metal you need for trailer wiring to work.


You need to be careful when using a wire brush to avoid damaging the pin connectors. A wire brush can be extremely aggressive and cause damage to plastic and metal. You can also damage the gap in the connector, which will not get you a connection for your wire when plugged into your truck.

Another disadvantage is that you are limited in the space and areas you can clean. Even a small wire brush is significant to the small spaces you need to get into to clean a plug. A brush will only go so far into the plug for cleaning. It is important not to jam the wire brush into the connectors as it will expand the gap and not give you an excellent connection to things light your running lights, turn signal, or even your electric brake.


What can’t WD-40 do? WD-40 seems to be the solution to everything. My father even used it on the threshold of our sliding door when it would stick. The only problem was that you would slip on that threshold because it was so slick!

Since everybody has a can of this stuff, it always seems like an option to try it out. What could it hurt…right? Using it as a trailer plug cleaner can work, although there are some things to consider before blasting your connector full of WD-40.

Use WD-40 lightly and with a towel

The first thing to remember is that WD-40 is more oil than solvent. What does this mean in this case? That it won’t evaporate and dry out. Whatever you spray with WD-40 will likely be full of oil for a while. So if you are going to use this stuff to clean your 7 pin plug, here are few things to consider.

Don’t spray the heck out of your connector. You don’t want to use it as a contact cleaner because it will not evaporate. Instead, give a quick surface squirt or spray onto a towel or rag. Then wipe down your connector. This will be the best option as you use the WD-40 as a cleaner on a cloth instead of dosing it with oil.


It’s cheap, and everybody has a can of this stuff. They sell it at grocery stores and every gas station you can find.

When used properly with a towel or rag, it can work as a solvent.


Because it’s cheap, people tend to overuse and spray way too much of this stuff! In the case of your plug, you are not trying to stop a squeak, so there is no need to spray and fill the 7 pin connector with oil.

It will hold dirt. Since it is an oil, it will attract dirt and debris from being exposed to the elements. In the long term, this can give you more trouble and more necessary cleaning.

Pipe Cleaner

Pipe cleaner? What is that? These are those straight-wired brushes that people use for crafts. They are thin wire, usually braided, with a synthetic material wrapped around them.

These are great for cleaning the connector for your trailer because they are small and have just enough cleaning power to get into the tight spaces of a corroded plug.

Pipe cleaners get in the small spaces without damage

Use them with a solvent or contact cleaner first. You can use the contact cleaner or a light coat of WD-40 mentioned above. Gently insert the pipe cleaner into the female connector. Since the pipe cleaner is small with those synthetic fibers, it can clean the hard-to-reach places of the connector without damaging them.


Small wires can get into very tight areas and provide a mechanical cleaning of dirt and corrosion. They are also gentle enough that you will not easily damage your plug or its connectors.


Not everyone has these things lying around. I find mine at a craft shop. They are cheap, I usually get hundreds of them for a couple of dollars. But you do need to go and find them.

They are also not great with a heavily corroded connector. Since they are gentle and small, they can only clean so much. But as we mentioned above, it is always good to start light in pressure and then work your way to more aggressive cleaning.

Vinegar and Water

If Vinegar can clean your glass, why not your plug? Mixing a 50/50 solution, putting in a bottle, and spraying your connector can offer some cleaning. The acid in the Vinegar reacts with the corrosion and is always used as a cleaning agent.

Proceed with this method similar to the WD-40 mentioned above. Don’t blast your connector with Vinegar, instead, give it a light spray and let it set for a few minutes. Then go back and wipe it down with a towel or rag.


Most people have Vinegar lying around, which can be a quick way to make up. It’s all-natural and is a great multi-purpose cleaner.


It can be a pain to mix up a bottle of Vinegar and water. If you are driving around, you likely don’t have a bottle of this pre-mixed in your tow vehicle.

Also, it is an OK solvent cleaner. It will work for a light cleaning, but heavy-duty corrosion requires a stronger mechanical method than we reviewed above.

Dielectric Grease

Once you have cleaned your plug, I suggest you use dielectric grease on the plug and the wiring harness pins. Dielectric grease will help keep out moisture and keep your connector from getting dirty and corroding quickly. The key is to use a light coating and not to glob it on. Too much will act more as a dirt attractor than a water and corrosion repellent.

Final Thoughts

There are several ways to clean your trailer plug, and we reviewed the best 5 solutions. With heavily corroded pins, you will need to use mechanical methods such as a wire brush or pipe cleaner. And for light cleaning, using a contact cleaner or solvent may do the trick! And once cleaned, give your plug a thin layer of dielectric grease to keep the connections watertight and corrosion free.