Why are 7-pin connectors so sloppy?

[skipmarcy]

Do ya think it could possibly be one of the wires inside the connector making/breaking contact ? Spades/pins aren't the only electrical connection necessary. Open that baby up and have a look at the condition inside. Or possibly a butt connector or scotch-loc that shouldn't be used anyway in the harness … Was a mechanic for close to 50 years and saw all kinds stuff that "worked for years like that". I ALWAYS soldered and heat-shrinked wires and took my time and properly wired the connector inside and then sealed where the wires go into the connector with silicone. Dielectric grease on actual connections inside and outside. My stuff works when I need it. Personally I don't care for the round pin connectors, I prefer good heavy flat terminals in a trailer plug/connector. Doing automotive diagnostics for so many years I've seen how round pins compare to flat pins for durability to abuse.

 

[nikerret]

My trailer has never given me a problem, but others I’ve pulled have. On the car trailer, we out a metal plug on. That helped, for quite a while. One of the HD trailers (14k tag) I pull, sometimes, has a new plug. The first few miles were rough. After I bent the tabs, for more pressure, it worked fine. One of the first posts hit the nail on the head, for immediate fixes.

 

[RichNJKubota]

Do ya think it could possibly be one of the wires inside the connector making/breaking contact ? Spades/pins aren't the only electrical connection necessary. Open that baby up and have a look at the condition inside. Or possibly a butt connector or scotch-loc that shouldn't be used anyway in the harness … Was a mechanic for close to 50 years and saw all kinds stuff that "worked for years like that". I ALWAYS soldered and heat-shrinked wires and took my time and properly wired the connector inside and then sealed where the wires go into the connector with silicone. Dielectric grease on actual connections inside and outside. My stuff works when I need it. Personally I don't care for the round pin connectors, I prefer good heavy flat terminals in a trailer plug/connector. Doing automotive diagnostics for so many years I've seen how round pins compare to flat pins for durability to abuse.

What Skip says here is very important.
Solder all wire to wire connections. Then use heat shrink with silicon sealant inside the heat shrink.
To keep contacts from corroding use dielectric grease, regular grease, oil, or Fluid Film.

I have not found anything better that will last for years and years out in the weather.
All the trailers I've owned have come with crimp connectors - from the factory. They will always fail. But worse than that they allow water to get into the wire and the entire wire from end to end will corrode so now the wire must be replaced.

 

[Sonny580]

my 7-pin flats are sloppy too. I dont use them much so gotta fight them every time I hook up the trailer. Neighbor bends his so they fit better and has great luck with them, but then he uses his trailers every day.
I still need to change mine to the type we had on our semi's way back when I drove. --- never had any trouble with them.

 

[sklunk]

every person I talked to who installed this, said their issues vanished, if they kept it clean

Amazon.com: EZ CONNECTOR S710 Trailer Side Elec Socket : Automotive

Buy EZ CONNECTOR S710 Trailer Side Elec Socket: Connectors - Amazon.com ✓ FREE DELIVERY possible on eligible purchases

www.amazon.com

The EZ Connectors are GREAT!
Unfortunately they are also a little pricey (around $120 for both sides) but like you said everybody I know that has one loves them and has never had any problems. The newer version comes with self-sealing plug holders for when you don't have the trailer connected.

 

[Gee Ray]

I tied a very small cloth bungee around the wire and pull the plug toward the truck. I put several thousand miles on the truck like that before I got a new trailer and new plug.

 

[jaxs]

4 forces work in unison to cause poor/intermintent contact on those plugs. #1 Heavy cord moving/wiggling plug which progressivly increasses clearance between contact points. #2 Loose contacts increase resistance and resistance translate's to heat when it come's to electric current #3 Internal parts become annealed from repeated heating and cooling. #4 Heat create's a resistive coating at contact points. Each force feed's and feed's off of other 3 so the process is like a run-a-way mine train picking up momentum until conections fail. The remedy in post 4 above doesn't last because annealing in force #3 make's metal soft and lose memory(spring).
The process can be slowed by supporting cord near plug and periodiclly cleaning contacts with something like DeoxIT followed with grease/preservitive.