30 years ago, Ford pick up trucks were equipped from the factory with 7 way ROUND PIN Pollack connectors, similar to the big trucks. I don't recall how they were wired though. Also 30 years ago, a lot of trailers were equipped with smaller diameter 6 way round pin connectors. A lot of confusion and a lot of hassle monkeying around to make everything work right.
At some point during the last quarter century, the RV industry seemed to universally standardize on the 7 way flat blade. All the vehicle OEM's began equipping their trucks and SUV's with the 7 way flat blade, if they offered a tow package.
I too, liked the older style all metal 7 way (and 9 way) round pin connectors with their anti kinking spring on the cables, and more robust construction overall. However, these types of connectors are not standard on RV and cargo trailers. They are simply not found. And no pick up truck manufacturer equips their vehicles with the older round pins either.
Given the risk that at some point, some other vehicle besides yours may need to move your trailer, the detriment of being different outweighs any perceived benefit of the more "robust" type of connectors. I'd stick with 7 way flat.
Hopkins, a brand available virtually in all automotive parts stores, including the big box chains like Pep Boys, OReilly's, Autozone, CarQuest, Napa, and the like, has what they market as an "ENDURANCE" line of vehicle connectors.
The specific model number is #48470, and it includes not only a 7 way flat RV blade, it also has a 4 way AND a 5 way flat universal plug integrated underneath. Both female receptacles have sturdy, tight fitting weather proof covers. The spring on the self closing 7 way flip up door is completely encapsulated on the hinge axis, unlike most door springs that are exposed and end up rusting. This enclosed return spring has a closure snap strong enough to put a decent bruise in your finger if you don't get your fingers out of the way.
The connector visually does have a goofy looking design... with an industrial looking hexagonal shape reminiscent of the "built Ford tough" commercials where you see the Ford logo slam shut and bolts turning nonsense. Don't worry, there is nothing Ford-esqe about this Hopkins connector, for you Dodge and Chevy diehards. I'm just using Ford's older commercials as an example of lame advertising and design that attempts to communicate industrial toughness but in the end only conveys a condescending attitude toward the consumer, who is given no credit for having intelligence to see the gimmicks as what they are... fluff that gets in the way of understanding the product.
Such is the style of this Hopkins connector. Despite it's cheesy looking Droid like so called "industrial" looking design, it really does have the most robust lifting door, as well as the longest supporting tube to hold the trailer connector in place. It also has the most compact face for having a 7 Way, a 5 Way, and a 4 Way connection capacity all integrated into one connector.
Getting back to the lifting door... it is the only door that I'm aware of that lifts up a full 180 degrees, so you can really swing it up out of the way to engage the trailer connector without bending so far down to the ground, if that is an issue for you. (I always squat down on my haunches anyway to engage chains and safety brake, but I can still appreciate this full swing door feature).
On the back end, the wire terminals do not appear to be brass... (unless they are nickel plated brass). I cannot report if this is a good or bad thing, because I do not know what type of metal these terminals are made of. I'm tempted to contact Hopkins to ask, as corrosion of wire terminals at their connections due to dissimilar metals is an important issue.
If I remember, I'll contact the company and report back. I have one of these units on my desk right now, unopened in the package. Expect to pay around $29.99.
PS... and you thought YOU overanalyzed everything? HA! :)
