Methods to Clean Contacts in 7-Way Trailer Socket on 2010 Dodge Ram 2500 Pickup

Question:

I was cleaning the factory 7 pin trailer plug and got sparks when I touched it with a wire brush. Is that normal? If not where should I look to fix it?

asked by: Zach

Expert Reply:

Inside your Ram's factory 7-way trailer socket are multiple lighting circuits and a 12V power circuit that is there to power an electric trailer tongue jack or to deliver a trickle charge to a battery mounted on the trailer.

If you refer to the linked photo you can see which function/circuit is assigned to each of the electrical contacts inside the connector. The 12V power circuit is carried on the pin at the 1:00 position as you look at the socket. If your wire brush were to contact the 12V power contact it could certainly cause a spark.

You may not have blown a fuse but it is easy enough to check. You can test the wiring to confirm it all still functions by plugging in your trailer and having a helper watch the various lights as you activate each one or you can use a circuit tester like # PTW2992 or a 7-way tester like # C73NR. Use of the circuit tester is shown in the linked video.

You might consider using a pencil eraser to clean those contacts or one of the available spray-on electrical contact cleaner products on the market, such as Caig De-Oxit.

expert reply by: Adam R