Trailer plug

super99 · Nov 24, 2019

Last summer I had to replace the trailer

plug on my new to me 98 Chevy 3500. Got it done and
everything worked.Hooked onto the trailer today and no lights.
The inside of the plug had some corrosion on a couple

of the ends. So I took the plug apart and found this mess.
When I replaced it last summer, I filled the back end around
the wires with black silicone to keep the moisture out. Looks
like that didn?t work. I?ll get another plug tomorrow and clean it
up and replace it. What can I do to keep this from happening
again? Thanks, Chris

TGP · Nov 24, 2019

Dielectric grease works well.

Just cover it liberally after connecting the wire and install.

Tom

Patsdeere · Nov 24, 2019

Agreed.

MARK ROBKE · Nov 24, 2019

Besides the dielectric grease on the terminals, I would put something around the harness to keep moisture out-it has to be a perfect seal-silicone should work well actually. Also I bet the most corroded terminal has constant voltage on it. Mark.

kcm.MN · Nov 24, 2019

Dielectric grease. Otherwise, nothing at all, but I'd go with the grease. If you're on the road a lot during winter months, then each winter you should check your connectors, thoroughly flush with warm soapy water, clear water rinse, dry, then re-grease. Road salts can wreak havoc on such connection.

Likewise, not all silicone is made equal. Many have additives that allow electrical current seepage, and even others can help contribute to corrosion similar to what you have.

There's a lot of people that don't accept that dielectric grease actually works, but I'm a definite believer!! It's real convenient to get the spray cans, but I prefer the squeeze tubes. I had a can lose its pressure, so I cut it open and used the remaining grease that way.

UncleTom · Nov 24, 2019

Grease is the best. There is no such thing as water proof.

DoubleO7 · Nov 24, 2019

https://www.etrailer.com/Wiring/Bar...gF1YZdb2PlFs_0MyFGJbHqPc-OFTwMXxoC-gkQAvD_BwE

Sealed connector where wires come into the back.
Nine foot long cable so thar you can solder the wires and wrap it up with rubber electrical tape etc.
Up out of the road spray, etc.

9001ron · Nov 24, 2019

Join the club ! Damage from road salt --- there should be a law against it but the car companies are making a killing replacing rusted out cars . Every time I hook up my trailer there is a 2 to 3 hour delay trouble shooting the lights or the brakes and then patch fixing . On your plug I would smear the inside with grease that would protect the screw connections. Other connections under the back of the truck need to be soldered connections with heat shrink tubing . You will still get corrosion on the exposed plug in ends as that trap door dosent seal out moisture . Perhaps spray in there with wd40 occasionally -- then it will be full of dust if you travel on dirt roads . I leave the connector end loose and then put a plastic bag over it and tape tight. You are still going to have trouble though -- carry spare plugs and wire repair ends with you in the glove box. One time I had to cut up a good extension cord and hook one end to the battery post -- ran it back over the top of the cab and box to the back just to get the running lights to work when I had to make a return trip after dark.

jeffcat · Nov 24, 2019

Nothing like some salt corrosion. Give it a good spray of that Fluid Film stuff. Works pretty good.

504-2 · Nov 24, 2019

There is a chemical reaction from silicon that eats copper. I found this out after I did just what you did.

Bob Harvey · Nov 24, 2019

Pack the whole thing with Vaseline. That is what the Gill Net fishers do with the 'float lights' for the ends of their nets. Works for the whole season, often just change batteries and repack. HTH

Steve@Advance · Nov 24, 2019

I was trying to find a part number for it, but Hopkins makes a plug that has the pigtail wiring epoxied into the back of the plug, completely sealed. I've found them at Northern Tool.

That way the connections don't get wet. Splice in the wires with solder, liquid electric tape, and shrink tube.

One other thing to do, if possible slant the plug down so water can't pool inside the open end.

Steve@Advance · Nov 24, 2019

One other thing, the #4 terminal is always hot.

If you don't need it, or rarely need it, trace it to it's source, put in a switch or pull the fuse/circuit breaker.

The always present voltage causes the corrosion between the wet terminals.

RBnWA · Nov 24, 2019

I use dielectric grease. RB

Geo-TH,In · Nov 24, 2019

Chris,
I had the same problem. Went to RV sales and bought a cord with molded plug end. Problem solved

George

JD Seller · Nov 24, 2019

Chris spray the plug front and back with Fluid Film. I started doing that ten years ago and my plugs last for years now.

RobCons · Nov 25, 2019

Molded plugs are the way to go. I've bought them and junction boxes from Amazon.

Geo-TH,In · Nov 25, 2019

X2,
A good trailer plug is also your life line to your
electric brakes. Don't be cheap, get a good molded
plug.
geo

John T · Nov 25, 2019

Having owned RV's for 49 years as well as a ton of truck and trailers what's worked for me is DIELECTRIC GREASE. I also tape and seal the plugs as much as possible once wiring is completed and keep them out of rain and water as much as possible. I ALSO like the molded ones as they can be better sealed then the do it yourself units. If theres no water or no oxygen present less oxidation and corrosion.

Its electrical so lotsssssss of opinions as usual

John T

Bill Tattersall · Nov 25, 2019

Try Boeshield T-8. We even use it for tools we use underwater in diving operations. Works great on my trailer plugs.

Russ from MN · Nov 25, 2019

Some silicone is not suitable for electrical use, it's actually corrosive!

Trailer plug

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Well-known Member

Member

Well-known Member

Similar threads