Hi There,Having issues with the 7 Pin trailer connection between my trailer and TV. I can't seem to get all contacts connecting at once - I I jiggle the connection slightly I can get brakes connected but I lose one or more light connections and vice-versa.I've tried using a very find grade wet/dry sandpaper to clean the contacts but that only brought minor improvements. I'm thinking that maybe the connections are too sloppy and maybe I need to replace the trailer connector plug. The trailer is 18 years old.I'd welcome any suggestions on this - not sure how difficult it is to replace the connector too. Also, because I have a hensley hitch that added a few inches to the trailer length, I don't have any room to lose length on the electrical cable (which I figure might happen when I replace the connector plug). If anything I need to make it longer.Any help much appreciated,Daniel.

Sometimes I have to use a screwdriver to bend the prongs for better contact. I use lithium grease on my wife's plug-in Prius cord, and that really helps.

Some plugs on trailer cords have an undersized diameter on the plug, so they fit really loose and sloppy in a truck OEM plug.I had the same problem. I replaced the entire cord / molded plug with a different brand, problem solved.

I replaced my 7 pin connector and no problems since.

That happened to me a long time ago.. I took a small flat blade screw diver and pulled the 'female' side prongs out in each socket and then sprayed some wd40 into the plug and that fixed it.. It was only a plug connection issue in my case, but if it's a wiring issue, then more work will need to be done to diag it..Good luck, Mitch

Thanks for the replies. Pretty sure the wiring is fine so I guess I'll start with the screwdriver and WD40. Hopefully its that simple:)

Problems with 7 Pin Connector | Good Sam Community

BB_TX
Nomad
Feb 21, 2021
Had similar problem. I have two factory 7 pin connectors on the truck, bumper and in-bed. The 7 pin trailer cord worked fine plugged into the bumper connector, but was intermittent plugged into the in-bed connector. After messing with it a long time and never getting much better, I just replace the in-bed connector and no more problem.
opnspaces
Navigator II
Feb 21, 2021
Hey OP I had the same problem once and fought it for an entire season. Finally having had enough frustration I went with the plug/cord set like posted by Gdetrailer. I replace the plug a few years ago and have not had a problem since. If and when the plug gets loose I'll spend another 20 - 30 dollars and replace it all again.
Gdetrailer wrote:

For less than $30 you can buy not only the plug but the entire harness with the plug molded in to the harness with 8ft of wire..

FOUND HERE

That one looked interesting since it has double prong contacts in the plug rather than standard single prong contacts..
Lakeland_Bob
Explorer
Feb 23, 2021
Just a word of advise. I replaced the 7 pin cord on one of my trailers with one that was molded together. After making the change, along with adding a connection box for easier repairs in the future, the lights
wouldn't work.

Thought I had screwed something up and looked for hours for the problem, knowing it couldn't be the cord/plug assembly as it was factory fresh.

I finally put my multimeter to the plug and wire ends and discovered the the cord was wired totally wrong, with only the ground wire being correct.

So my suggestion would be that if you change the entire plug/cord assembly, check the continuity between the wires and their correct pins as indicated in a wiring diagram.

Oh, I went ahead and used the cord/plug I had, made a note on what wires went to the what prongs and put the note in the connection box for me for later reference.
Grit_dog
Navigator
Feb 23, 2021
Ha, I thought the same a few years ago grabbed one of those pre molded pigtails to fix a trialed at work real quick. Found out after the fact and cussing at it that there are 2 different 7 pin wiring color conventions
JRscooby
Explorer II
Feb 23, 2021
About 10 years ago I had a recital/cranial inversion while moving trailer around in the lot, and mangled the plug. When I replaced it, hooked up tested all lights and brakes. Then I pulled the cap lose, buried all screws and connections in clear silicone, put a bunch in the cap, and put it back together. A lot was forced out around the cord. Wiped all the excess off. Keep the socket well lubed with di-lectric grease, no more problems. (also made a place that holds the end when not hooked up)
rhagfo
Explorer III
Feb 23, 2021
Gdetrailer wrote:
You can try to clean them, scrub them, adjust the prongs but after a while weather and age takes a toll on the plugs..

For $6 and a little bit of your time you can just replace the plug and be done with the issue for quit some time..

FOUND HERE

For less than $30 you can buy not only the plug but the entire harness with the plug molded in to the harness with 8ft of wire..

FOUND HERE

That one looked interesting since it has double prong contacts in the plug rather than standard single prong contacts..

To the OP, you have 13 year in Minnesota on your connection is your TV is still the 2003 Explorer Limited 4X4 V8 Advancetrac 3.73 Axle. Spend a couple dollars and get new connections, buy the best you can find.
Gdetrailer
Explorer III
Feb 23, 2021
JRscooby wrote:
About 10 years ago I had a recital/cranial inversion while moving trailer around in the lot, and mangled the plug. When I replaced it, hooked up tested all lights and brakes. Then I pulled the cap lose, buried all screws and connections in clear silicone, put a bunch in the cap, and put it back together. A lot was forced out around the cord. Wiped all the excess off. Keep the socket well lubed with di-lectric grease, no more problems. (also made a place that holds the end when not hooked up)

Standard "RTV" silicones use acedic acid as part of the curing process.

Generally not recommended for use with electrical connections.

May work for a while but may have enough acid to eventually damage the wire you were protecting.

They do make "neutral cure" RTV which is a bit electrical connection friendly and a better choice over all for this use.
JRscooby
Explorer II
Feb 23, 2021
Gdetrailer wrote:
JRscooby wrote:
About 10 years ago I had a recital/cranial inversion while moving trailer around in the lot, and mangled the plug. When I replaced it, hooked up tested all lights and brakes. Then I pulled the cap lose, buried all screws and connections in clear silicone, put a bunch in the cap, and put it back together. A lot was forced out around the cord. Wiped all the excess off. Keep the socket well lubed with di-lectric grease, no more problems. (also made a place that holds the end when not hooked up)

Standard "RTV" silicones use acedic acid as part of the curing process.

Generally not recommended for use with electrical connections.

May work for a while but may have enough acid to eventually damage the wire you were protecting.

They do make "neutral cure" RTV which is a bit electrical connection friendly and a better choice over all for this use.

Going back decades, I have filled crimp connecters with cheap silicone form-a-gasket before putting wires in and crimping, to wire truck and trailer lights. 1 rebuilt wreck was towed about 100,000 miles a year for 18 years before I sold it. Replaced lamps, and the cord a few times, but the acid never hurt the wires. And the road salts and grime didn't either.
Gdetrailer
Explorer III
Feb 23, 2021
JRscooby wrote:
Gdetrailer wrote:
JRscooby wrote:
About 10 years ago I had a recital/cranial inversion while moving trailer around in the lot, and mangled the plug. When I replaced it, hooked up tested all lights and brakes. Then I pulled the cap lose, buried all screws and connections in clear silicone, put a bunch in the cap, and put it back together. A lot was forced out around the cord. Wiped all the excess off. Keep the socket well lubed with di-lectric grease, no more problems. (also made a place that holds the end when not hooked up)

Standard "RTV" silicones use acedic acid as part of the curing process.

Generally not recommended for use with electrical connections.

May work for a while but may have enough acid to eventually damage the wire you were protecting.

They do make "neutral cure" RTV which is a bit electrical connection friendly and a better choice over all for this use.

Going back decades, I have filled crimp connecters with cheap silicone form-a-gasket before putting wires in and crimping, to wire truck and trailer lights. 1 rebuilt wreck was towed about 100,000 miles a year for 18 years before I sold it. Replaced lamps, and the cord a few times, but the acid never hurt the wires. And the road salts and grime didn't either.

Agreed.

Have done the same thing, however, as I learned along the way of life, just because you did something or used something didn't necessarily mean it was a "good thing" or "recommended thing"..

It just means you "got away with it"..

Once I started working with a lot of other electrical techs, I was "corrected" as to use the recommended materials for the job at hand.

Additionally was introduced to self adhesive heat shrink tubing which uses a heat activated glue/sealer layer inside the tubing for electrical connections used outdoors when water intrusion is a high possibility..

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