7 pole trailer connectors

[Dallas_Lilly]

Good Morning All, I was hoping somebody could give a advice on a different type of 7 pole trailer plugs. I have 5 trailers, a car hauler, dump trailer, camp trailer and two horse trailers, all have 7 pole flat plugs similar to this 7-Way Molded Trailer Wire Connector, 3' Long Hopkins Wiring H20042

I have even went as far as installing waterproof junction boxes on the trailers to make the connections rather than splicing wires and having a connection that can corrode.

On my truck I have a plug similar to this Hopkins Multi-Tow 7-Way Blade and 4-Way Flat Trailer Connector - Toyota Hopkins Wiring HM43374 except for a chevy.

My problem is this, the plugs last for about 6 months to a year and then inevitably one of the connections gets loose and doesn't always make contact! right now it is the tail light contact and driving down the road I can hit a bump and and watch the marker lights flicker. Now I know most would think loose connection or ground but when I got home I could wiggle the plug at the truck and watch it go on and off.

Does anybody have a suggestion of better plugs? I am OK with changing style and am capable of wiring something completely different. I would love to keep the factory wiring in tack on the truck but if need be I can change that too.

Any ideas?

 

[PoorPlowboy]

Subscribe because I am in the same boat as you and don't know what to do. I'm tired of fiddling with the plugs every time.

 

[mikehaugen]

I too have been looking for a good vehicle side socket because mine usually get corroded quickly, despite having the lid and using ample die-electric grease. I haven't found one yet, but have considered going to a mil-spec canon plug like shown here-they are waterproof and thread together. (we use them at work and I know about their durability and sealing) The problem being is that 1) I would have to do all my trailers and then I have "odd" trailer plugs that would only work with my vehicles, and 2) I have an odd vehicle that will only work with my trailers. I rent trailers occasionally, lend them out occasionally, and borrow occasionally, so this wouldn't work very well. I guess I could make some adapter pigtails to standardize them, but that seems like a lot of time and money when I can just buy a new socket every year or two and deal with it. Maybe someone will have a good solution for both of us.

ICC | Military Connectors, Backshells and Accessories - Circular, Rectangular, Fiber Optic, RF and more

 

[HarryVanderpool]

Your Idea of terminatind the wires in a waterproof box is a good one. That is the way I have my trailers set up also.
I have never used your style of connectors, but if they don't work; they don't work.
Here is what I use and I have absolutly no problems year after year:
Pollak Heavy-Duty, 7-Pole, Round Pin, Trailer Wiring Connector - Trailer End Pollak Wiring PK11700
There is no reason to be fighting your trailer connections all the time. You have better things to do.
I would also look at it as a safty issue.

 

[Ed L]

I'm needing to upgrade also, tired of using the now oddball 6 pin round plug. Wanting to switch to the RV style as that is the new "standard".

Ed

 

[Diamondpilot]

I have never had any trouble that I did not cause. All mine on the trucks are factory. I tow a lot and just never had a issue.

Chris

 

[5picker]

Gosh Dallas_Lilly... I don't know what to tell you.
I'm like Diamondpilot... I've just never had a problem with them that wasn't caused by me.
I have 5 trailers and tow a lot.
Once, I didn't get the plug seated until it latched and the plug fell out and dragged the ground. I had to replace that one.
On one trailer, my brother ran over the plug after he unhooked the trailer and was backing away from it so it was mashed.

Unless your harness is too short and it's pulling on them... or you are not pushing the plug straight in when coupling, I don't know what to tell you.
That plug should be able to be coupled hundreds of times without a failure. Mine are and work fine.
Those 7 pole flat connectors are the industry standard for a reason... I'm just not sure what your reason is for having so much trouble?

 

[5picker]

One other thought... you mentioned you could wiggle the plug... does your connector socket lids not have the latch that holds the plug tight into the socket when coupled?
Just a thought.

When mine are inserted and latched, they are really tight... no wiggling.

 

[RobertN]

Same... Truck is 12 years old; truck "receptacle" still works fine. Her ein central Calif foothil "Gold Country", I do not have the salt and stuff you guys in the east see though.

I have never had any trouble that I did not cause. All mine on the trucks are factory. I tow a lot and just never had a issue.

Chris

 

[Ford850]

5picker is right. Your lid should be locked to the top of the plug to hold it in place. Some people use a 1 1/2" o-ring to snug the lid to the plug, or even a zip strip. Also, keep the connections lubed well so you are not breaking something loose when trying to disconnect. Any grease will work, but Fluid Film works great and is easy to spray all metal connectors inside and out.

 

[Egon]

Dielectric grease.:thumbsup:

 

[newbury]

Timely thread -
I just rented a trailer to haul my new to me Kubota M4700 - Yesterday, in the rain, the trailer rental guy couldn't get the trailer running lights to stay on, (turn signals and brake lights worked) hooking up the tester to both the 4 prong & 7 prong (like Hopkins Multi-Tow 7-Way Blade and 4-Way Flat Trailer Connector - Toyota Hopkins Wiring HM43374) the tester would flicker when the trailer was on the ball. Took the trailer off the truck, the tester glowed solid. Couldn't rent the trailer without running lights in the rain.

Went back today, sunny, rented the trailer. Didn't ask about running lights.

Can my plug need replacing?

 

[Dallas_Lilly]

Thanks for the replies guys! I have a good cap and it is snug... It think what is happening is the actual contact on the truck or the trailer is not making contact because of corrosion. I am here in Arizona but at 7K feet elevation and for the last few years they have started using chemicals on the road, I do use dielectric grease on both ends but this stuff is horrible that they are using on the roads. That was the reason for the water proof junction boxes, but connectors and the like just dont cut it around here any more. Heat shrink works well also but if I have to replace the molded cable i then have to butcher everything again.

I like the idea of the military spec connectors, yes I would have to change all my trailers and it wouldn't be to industry standard but if someone needed to borrow one of my trailers I could make an adapter to go to a standard 7 pole flat..

I dont know though I could probably replace many more of the standard connectors for the price of the mil spec connectors...

 

[lostcause]

i've had my current truck for a little over 6 years, and i've never done any maintenance on the factory 7 way plug, and it's always worked. on prior vehicles where i had to install the plug myself i also never had issues. the only thing i've gone on my own installations is to make sure the wire is wrapped around the screw well, and then probably overtightened. after that i try to force a little extra of the wiring inside the plug / coupler before i tighten the strain relief screw. that just adds a little extra cushion if there is anything pulling on the wires, like massive chunks of ice. in the past i have also put a gob of silicone through and around the wires where it enters the truck side receptacle because in the winter months there is a large volume of crap spraying the underside of my vehicle. my truck is currently completely covered in a nice layer of dried road sand - about 1/16"-1/8" thick, and when i hooked up the trailer yesterday i had a nice clean socket. the only plugs i've ever had any problem with are the 4 way flat trailer plugs, which just don't fare too well up here.

 

[Dallas_Lilly]

I think I may have found what I need! This is pretty dang cool if you ask me... A little spendy though my frustration level may go down a bit....

http://ezconnector.com/

 

[5picker]

I think I may have found what I need! This is pretty dang cool if you ask me... A little spendy though my frustration level may go down a bit....

http://ezconnector.com/

No question that will help keep out the crud.
It's something though that's not 'standard' and like you said... if anyone borrows your trailers, they will need an adapter and/or if you tow someone else's trailer, you'll need the same.
If they would have added those sealing o-rings to a standard 7 pole flat connector it, would have served the same purpose and been compatible with industry standard... but maybe there are some copyright infringements or something?

We get a lot of crud here in the mountains of PA and I keep my plugs clean and use dielectric grease. Like I said, never a problem.
You might source an o-ring the proper size to slide on the outside of the plug and accomplish something similar.

Your idea of using a weatherproof junction box to replace the pigtail is good. Enclosed connections are always better than exposed butt connectors.

Personally, I don't care much for the molded connector/pigtail.
A lot of times when they manufacture those things they don't do a good job of attaching the wires to the connectors inside the plug.
I spent a lot of years as an automotive electrical technician and I've cut several of those types of connectors apart and a lot of times they just touch the wire to the connector tab and 'hope' the plastic which is molded around it, holds everything in place.
Unfortunately it doesn't... not for very long anyway.

If changing a plug I like to use something like this...

This way I know my connections are credible.

 

[r8nger]

Answere is simple, go to Fleetpride or any other heavy truck parts supplier and buy the plugs they use on tractor trailers. Buy the aluminum ones , not plastic, once you get everything changed over, they'll last a long time . 7 pin/ all round connectors, you can buy just the ends, then make an adapter for the odd occasion that you use someone else's trailer with the tv style flat blade plug

 

[Dallas_Lilly]

Answere is simple, go to Fleetpride or any other heavy truck parts supplier and buy the plugs they use on tractor trailers. Buy the aluminum ones , not plastic, once you get everything changed over, they'll last a long time . 7 pin/ all round connectors, you can buy just the ends, then make an adapter for the odd occasion that you use someone else's trailer with the tv style flat blade plug

That is a good idea. Flagstaff has 3 truck shops that could source those for me. They would have to be good if they service the tractor trailer industry...

 

[Dallas_Lilly]

I never thought about the connection inside the plug possibly giving me the problem, that very well could be and I am blaming the wrong part of the plug... I could solder the connections to the plug you have showed but what concerns me with those is keeping the crud out of the plug where the wires enter, that is not a weather proof connection unless you silicone it or something...

No question that will help keep out the crud.
It's something though that's not 'standard' and like you said... if anyone borrows your trailers, they will need an adapter and/or if you tow someone else's trailer, you'll need the same.
If they would have added those sealing o-rings to a standard 7 pole flat connector it, would have served the same purpose and been compatible with industry standard... but maybe there are some copyright infringements or something?

We get a lot of crud here in the mountains of PA and I keep my plugs clean and use dielectric grease. Like I said, never a problem.
You might source an o-ring the proper size to slide on the outside of the plug and accomplish something similar.

Your idea of using a weatherproof junction box to replace the pigtail is good. Enclosed connections are always better than exposed butt connectors.

Personally, I don't care much for the molded connector/pigtail.
A lot of times when they manufacture those things they don't do a good job of attaching the wires to the connectors inside the plug.
I spent a lot of years as an automotive electrical technician and I've cut several of those types of connectors apart and a lot of times they just touch the wire to the connector tab and 'hope' the plastic which is molded around it, holds everything in place.
Unfortunately it doesn't... not for very long anyway.

If changing a plug I like to use something like this...

This way I know my connections are credible.

 

[not2old]

I used to have problems but have eliminated them by going overboard on the installation of the female connection. I remove one of my license plate lights and grind out the hole to fit,so that the receptacle is located out of all the crud/spray that covers under the bumper. I then solder ring terminals to all wires before securing them to the screws. Any splices I make are all soldered and covered with heat shrink tubing before being well taped and then I pop rivet the connector to the bumper. Using this method, I've not had to repair anything on my truck. It is however, a big pain in the butt if I have to remove the bumper.