Melted RV shore-power plugs happen far more often than you would imagine. The sight of a melted plug is, at the very least, alarming and, at worst, can cause a fire. Preventing a melted RV shore power plug is easy and simple. Normally, only two conditions will melt your plug, and we'll tackle both of them so you can prevent what could be a frightening and dangerous situation.

The Causes of Melted RV Shore Power Plugs

RV shore power plugs melt due to corrosion and loose connections. Removing corrosion is an easy fix if you catch it in time. Loose connections frequently stem from overheating/overloading your wires and connectors. Understanding the safe operation of your electricity draw and having the proper equipment can save your system from poor connections and subsequent complications.

Corrosion: It Happens in All Climates, But Frequently Goes Unnoticed

Corrosion happens, but depending on the climate, some is more visible than others. If you're near the ocean, a thick layer of corrosion on metal plug prongs can develop quickly and screams for attention. Where I live in Colorado, a dull layer of almost invisible corrosion can also develop rapidly and can be even more dangerous because it's barely noticeable.

How Corrosion Can Start a Fire

When RV extension cords, adapters, and surge protectors are connected, the act of the two sides of the connector surface area coming together usually scratches through any corrosion and makes a small surface connection. However, the poor connection means that all of the electrons are coursing through a smaller area than intended, creating heat.

RVs frequently draw close to the maximum amperage supplied by the source, especially in summer when the air conditioners are running or in winter when the electric heaters are running. 50 Amps is a lot of power.

This Fix is Simple: Prevent the Corrosion

It's that easy. Keep your connectors shiny and clean, and you'll avoid this serious problem.

Rub the prongs on the male plug with fine-grit sandpaper or steel wool. Then, coat the connections with a fine layer of Dielectric Grease.

You probably won't need to clean the female outlet on the pedestal since the park owners are responsible for keeping the receptacle on the RV park pedestal clean. However, if you have an RV outlet installed at your home or you are using your own 30 or 50 Amp RV Extension Cord, you might need to clean the receptacle end occasionally.

Since this part of the process is a little more difficult, you'll need the right tool to get in there and effect the cleaning.

Turn the Power Off Before Cleaning

I use a metal contact cleaner file to clean the outlet's recessed female terminals. Make sure the power is off before inserting anything into an outlet.

Spray Contact Cleaner into the socket, then work the cleaner file in and out to loosen the corrosion. Spray Contact Cleaner again to dislodge and remove the loosened corrosion, allowing it to rinse out.

Add just a drop of Dielectric Grease to each male terminal.

Drawing Power: Heating and Cooling Over Time Loosens the Connection

While corrosion and loose-fitting connections are most often the problem, using an extension cord that is too light and/or drawing near the maximum current causes the wires and connectors to heat up and cool down, expanding and contracting repeatedly, damaging them over time and causing a loose fit. This is most frequently a problem for RVs that use 30 Amps.

Be mindful of how much current you're using. For example, if the A/C is running, turn at least one off before using the microwave oven, as both appliances draw a significant amount of power.

Replacing a Burned or Melted RV Shore Power Plug

Replacing a damaged RV Shore Power Plug is easy and straightforward. The plug is relatively large, so you have plenty of room to route the wires.

Cut back the black outside rubber insulation of the power cord to expose enough non-burned inner wires, as shown. Cut off the burned and melted wire.

Insert the cable into the plug until the outer jacket is completely under the metal clamp. Tighten the clamp screws securely.

Strip the insulation off the inner wires about 1/2" to expose the shiny copper wire. Twist the wire strands together.

Loosen the three terminal clamps and slip only the exposed copper wire under each clamp. Ensure every strand gets under the clamp and no strands touch any other terminal. Follow the color code like the diagram shows with the plug you buy.

Replace the outer cover and tighten the three screws that hold it. That's it. You're done!

Publishers Note:  Always turn the RV park circuit breaker Off when plugging in or unplugging your shore power cord. This prevents arcing when only part of the plug is in the receptacle. You always want your power plug plugged completely in when the power is turned On or Off as this will extend the life of your connectors.  

Cleaning an RV Trailer Connector

Corrosion on your 7-pin trailer connector can cause intermittent loss of turn signals and brake lights on your trailer or toad.

There are several types of connectors in use.

Cleaning the 7-Pin Round Style RV Trailer Connector

Cleaning the 7-pin round-style RV trailer plug is similar to cleaning the shore power plug described above.

Getting to the smaller terminals is always the tricky part. A Terminal Cleaning Tool or Ignition Point File is handy to have.

 Cleaning and Repairing a 7-Pin Molex Connector

Cleaning a Molex connector can be difficult if your trailer or toad has one. Lucky for us, someone has invented a cleaning tool. The picture above is a terminal removal tool, but it's perfect for getting in there and scratching the corrosion of the tiny terminals. You could also use the tool to remove the pin, clean it, and reinsert it into the nylon housing if it is extremely corroded.

Apply a quick squirt of Contact Cleaner. Scratch and spray the surface until the tiny pins are clean and shiny. Finish with a quick spray of Corrosion Inhibitor. This will prevent or delay further corrosion. 

Another easy method of cleaning the recessed connectors is to spray them with Contact Cleaner, then plug and unplug them several times.

If the Connector’s Pins are extremely corroded and need to be replaced, it's easy now that you have the Extraction Tool.

Corrosion In Your RV Power Center

Are the lights in your RV flickering? Is the fan in your power center running constantly? Are your circuit breakers popping? Do you smell something getting hot?

Check your RV's power center for loose and corroded wires and connectors.

Unplug your RV from the power pedestal (or generator) and let it discharge for about twenty minutes. Also, disconnect your house batteries if a secondary load center is fed through an inverter. Then, removing the circuit breakers and cleaning the contacts and connectors is safe.

This power center was on the way to a catastrophic failure, which could have burned down the RV.

Corrosion Is Going To Happen. Catch It Before It Becomes a Problem

Add checking for corrosion to your list of to-do items during your spring de-winterizing. Check the battery terminals and clean them if needed.  Clean the shore power plug even if you can't see any corrosion. Open your power center and, using a flashlight, look closely at the connections. Clean or replace any components if needed.

At the very least, your electrical equipment, like the air conditioner, will run better.

You could save yourself a catastrophe.