Lights connection water greif

[ArlyA]

If you don't have one, a trailer light tester is a handy tool for under $15. It may help you find which wire(s) are having issues, which could indicate where the water you suspect might be.

If it was bothering my that much, I'd start with a good spray of circuit cleaner several times. If that didn't work, then see if the thing is able to be disassembled easily. If it is, disassemble and clean out. If not, maybe look into replacement. No idea the price of that connector.

As others have said, maybe there's another connector upstream of it that could be the culprit as well.

Good luck. These kinds of problems can be perturbing.

This only happens over the winter and when I spayed the connector on the bumper with wd-40, it went away. So that kind'a proves its moisture in the trailer connector.

 

[dodge man]

I have a Thule bike rack for my truck. It blocked my taillights mostly when bikes were on it. I added an LED strip to it that plugs into the flat four. Like Arly says, no brakes but it knows it’s there the minute you plug it in.

 

[Slowpoke Slim]

This only happens over the winter and when I spayed the connector on the bumper with wd-40, it went away. So that kind'a proves its moisture in the trailer connector

You know you could be getting moisture in more than just one single point along the wiring harness, right?

Check them all, or have fun with this issue all winter long.

 

[pmsmechanic]

I live on an area with numerous gravel which are hard on trailer plugs. I moved the plugs into the box on both of my trucks and that issue is gone. So is the salt water corrosion from the salt trucks in winter.

 

[RoostersGarage]

If you're not seeing moisture under the door when you open it, then I'd check at the backside of the connector where the wires come in. I'd imagine it's looking for the ground circuit to have a connection. Clean the backside with contact cleaner, blow it off with air, then put some silicone sealer on to seal it up if this is where the issue is.

 

[LD1]

I have had to replace the connector on a few late model chevy trucks because either something inside it fails, or one of the flat pins get corroded enough they break off.

Not sure if you said what model the truck was?

But the OEM wiring harness is probably good. And its an issue at the trailer plug connection that goes from the 7-way to the truck harness, or the 7-way receptacle itself. But they are pretty inexpensive.

They look something like this.....no cutting or splicing any wires.

https://shop.advanceautoparts.com/p/hopkins-40974-multi-tow-exact-fit-oem-replacement-7-blade-and-4-flat-towing-connector-40974/11195953-p?product_channel=local&store=7876&adtype=pla_with_promotion&product_channel=local&store_code=7876&gclid=Cj0KCQiAvqGcBhCJARIsAFQ5ke4w2_VaJdNU5fv3HWy2A7lCsDzCC7k1AtU4vL9bL2Pzj-muJMCom7YaAo1WEALw_wcB&gclsrc=aw.ds

 

[Brily Farms]

Silly question you guys. The trailer connection in our ford seems to gain moisture over winter months and the truck keeps telling us"trailer is connected" followed by "trailer is disconnected" over and over again. Of course we us liberal amounts of electricital grease on those connection's. Does anyone else have this greif?? What do you do for that? Our truck lives outside.

We had the same issue on our 2015 F-250 with our previous gooseneck trailer. When we replaced the trailer with a new model, the issue went away. That would suggest the issue is with the trailer plug, not the truck. Older plug on the previous trailer was not making good contact with the truck. I suggest you try replacing the plug on the trailer --- plugs are cheap and easy to change out. Just be sure to take a picture of the wiring on the plug before disconnecting the wires. Good luck either way. Nuisance issue to be sure.

 

[mstelts]

There was a service bulletin for 2016 F150s. That will fix it.

 

[LD1]

We had the same issue on our 2015 F-250 with our previous gooseneck trailer. When we replaced the trailer with a new model, the issue went away. That would suggest the issue is with the trailer plug, not the truck. Older plug on the previous trailer was not making good contact with the truck. I suggest you try replacing the plug on the trailer --- plugs are cheap and easy to change out. Just be sure to take a picture of the wiring on the plug before disconnecting the wires. Good luck either way. Nuisance issue to be sure.

He said he is having issues with NOTHING connected. But intermittently thinking something is connected. So not a trailer issue

 

[brbhan]

Silly question you guys. The trailer connection in our ford seems to gain moisture over winter months and the truck keeps telling us"trailer is connected" followed by "trailer is disconnected" over and over again. Of course we us liberal amounts of electricital grease on those connection's. Does anyone else have this greif?? What do you do for that? Our truck lives outside.

CRC Electronics Cleaner (Home Depot) sprayed periodically, helps. WD40 (Amazon) also makes a similar product

 

[nknelsen]

I've had the same problem. In my area the salt used to keep roads ice and snow free can get into your trucks trailer connection and salt mixed with whatever electrical grease you've used can conduct enough electrical current to fool the truck into thinking there may be a trailer when there isn't one.

Brass filings from lots of plug insertions can do this as well.

I had an oldsmobile once that would continue to signal long after a turn or the signal would sometimes come on by itself. The local gm dealer quoted me many hundreds of dollars to replace the entire switch assembly. I was able to open the switch body, wipe all of the old grease (full of brass filings) and applied new grease which solved the problem completely. I drove that car for quite a few more years before scrapping it with no signal issues.


I clean both the truck connection and the trailer plug with brake clean spray and reapply electrical contact grease to the trailer connector only. I then plug the trailer into the truck several times in and out to spread the contact grease.

I would try this first before looking at the wiring.

 

[Flogger]

Clean it well. Take dielectric grease and throw it in the trash. Dielectric grease is and insulator that provides corrosion a fine home. Search Amazon for No-ox_ide A. Apply it very sparingly to each individual connector. If all goes well you will be as impressed with the product as I have been for the last 30 years.

 

[ArlyA]

If you're not seeing moisture under the door when you open it, then I'd check at the backside of the connector where the wires come in. I'd imagine it's looking for the ground circuit to have a connection. Clean the backside with contact cleaner, blow it off with air, then put some silicone sealer on to seal it up if this is where the issue is.

Looking in it, while the computer is saying "trailer is connected" there is no appreciable water amongst the dia-electric grease.

 

[dodge man]

I assume your truck has both a 7 pin and a 4 pins hookup? Have you looked at the 4 pin? I searched a F150 forum I’m a member of, a couple people had the same problem but didn’t see a clear solution. If your like me you hate having to take it to the dealer but you might have to.

 

[ArlyA]

Its still under warrante and was to the dealership last winter. While there for another reason, I asked about this trailer computer grief and they did fix it and said "you do have good dia-electric grease in it, we dried it out and that fixed it". Of course the problem did show up again later. I did peak in the 7 pin slot but do not use it. But since they dried out the 4 pin and the computer grief stopped and I did the same thing with wd40 and that stopped it as well. That proves to me the problem is a slight amount of moisture in that plug.