7-way flat connector pinout

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My camper (2016 airstream) and vehicle (toyota) both have a 7-way flat connector. We purchased the camper many years ago and and it came with just a short "adapter" and I am trying to understand what its functional purpose is, and if I need to really be using it. Every wire goes straight from the same pin on the vehicle side to the trailer side, however on the vehicle side the ground has a wire connecting to the left, right, and running lights. There is something inside of shrink wrap on the wire, I'm assuming a diode?

Does anyone now what this is for? Camping world says they have no idea what I'm talking about. Is this something magic for toyotas, or something I should NOT be using if the previous owner had a different vehicle. Amazon and google are surprisingly unhelpful, and there is nothing on this adapter other than "tiwan" and "patented". I'm tempted to call tiwan and ask, but... starting here instead.

Thanks!
 

CharlesinGA

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Do you have separate (amber) turn signals on the Toyota? I bet you do. The brake lights and turn signals are totally separate on many new vehicles and all the Toyotas I have see are made this way.

The trailer on the other hand uses the same bulb and filiment for the brake and the turn signals.

I have never seen a flat 7 pin connector. RV's and Airstreams are no exception have a round 7 pin. If your Toyota does not have a factory installed 7 "pin" round connector, then this adapter is probably used to take separate turn and brake signals and combine them somehow, this is usually done with an electronic box in the cord.

Charles

Does it look like this? This is an Australian thing...........

3_Flat-7-Pin_3.jpg


kt744_diagram.jpg




This is what is found on American RV's and Trucks.

7-Way-RV-Style-Trailer-Plug-Wiring-Diagram-1.png


7-Way-RV-Style-Trailer-Plug-Wiring-Diagram-2.png
 
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This is what it looks like. Factory wiring harness, I have a 7-way and 4-way plug installed on my hitch from the factory. Its actually a 2022 Lexus GX460 (and same as my 2016 GX460) but same basics as a 4-runner and I imagine all Toyotas, they all come pre-wired for a trailer hitch even if you don't order it they just hide it under the bumper, and pre-wired for a brake controller which I also have.

I do have separate amber turn signals, so this concept makes sense, although weird that if every pin is connected the vehicle wouldn't send the power on the correct pin and this adapter would be unnecessary. And why to the ground... that isn't making sense to me unless I am reading the wiring diagram wrong and I've checked but will check again, and I'll stick the meter on the vehicle and see what I can see.

Apologies when I said 7 pin flat I meant the blades are flat, not the actual connector. Some 7 pin round connectors also have round pins and a different pinout, so I was attempting to be clear that this isn't "adapting" anything as far as I can tell. So its a normal 7 pin round connector with flat blades, same as any truck or anything I've ever seen.

This is the adapter, I took the cover off to see what it looks like and every pin is straight through and its just the white wire jumpered to green, red, and brown in the picture.
IMG_4014.jpeg
 
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It’s not a adapter. It’s just a standard plug. 99.9% of rv’s have this style.
99.9% of RVs require this special plug in addition to the normal RV plug? That doesn't make sense, and it doesn't make sense that camping world doesn't know what it is (although maybe I got the new guy). My tailer has a 7 pin round connector, my tow vehicle has a 7 ping round receptacle, why would I have to deal with this 3" long extension that jumps some wires if 99.9% of vehicles require it. It doesn't make sense to me, and its a point of failure / another thing that can come loose, needs to be stored, etc. Also due to the angle of my tailer receptacle this forces the wiring closer to the road, which is less than ideal, and this obviously doesn't flex.
 
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In case there is some confusion about what I'm talking about, this is it back together. It looks like they also used the same shell for other purposes like a 12v cigarette lighter socket, inside that area is completely empty. Pretty cheap for sure.

Anyway, if this isn't sounding familiar to anyone as I hoped it would I will do some more research tomorrow. I appreciate the replies, I was hoping for someone to say "ah ha! I know this", as the guy that sold us the camper assured us it was necessary, and I just hate not knowing why - especially if I break down or, like recently, get my wiring ripped off by a road hazard and have to understand how this works - not fun w/kids and dogs in the car on the side of the e-way.
 

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Krazeehorse33

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Didn’t some Airstreams come with a Bargman connector but unconventional wiring schematic? The adapter allowed you to use the trailer with a truck that had a conventionally wired connector.
 

Isaac-1

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I am not sure on the 7 blade variety, but on the 6 round pin plug there are 2 different possible wiring standards, one puts the trailer brakes on the center pin, and aux 12V on one of the outer ring pins, the other reverses those two wiring positions.
 

Krazeehorse33

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I would suggest registering on an Airstream forum and pose your question. My brother had an Airstream in the early to mid 80’s. It was a late 60’s or early 70’s model IIRC and I can check with him tomorrow if he recalls but I’m gaining confidence in my previous post but haven’t been able to confirm yet.
 
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Ok, a little research found that it's a 7-pin inline backup alarm adapter:

(Could be a different brand)
Wow, interesting find. I can't imagine how many people would want to kill me with an alarm while backing in to a camp site. It does look the same, but there isn't any kind of alarm mechanism in the plug, just the jumpers between wires. I could see it being the same chassis though, it sure looks the same. Honestly what I want is the opposite, I want an alarm that tells me when my trailer is NOT connected. I think my brake controller (a cheap curt one from amazon, which I am 50% convinced is a fake unless curt makes really really cheap controllers) will tell me by blinking something, but I can't easily see it (I can reach it though) where it is mounted. Not 100% sure though since it seems to have no issue if the trailer is not present. Honestly I'm freaked out that I drove 5 hours and have no idea when this stupid thing fell off. From now on my immediate plan at least is to always have my driving lights on (good idea anyway) and just constantly check for my side markers in the mirrors. Still, seems like someone would have come up with a better and consistent design given how seriously important lights, turn signals, and brakes are for anyone hauling.
 

NY_Dutch

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Wow, interesting find. I can't imagine how many people would want to kill me with an alarm while backing in to a camp site. It does look the same, but there isn't any kind of alarm mechanism in the plug, just the jumpers between wires. I could see it being the same chassis though, it sure looks the same. Honestly what I want is the opposite, I want an alarm that tells me when my trailer is NOT connected. I think my brake controller (a cheap curt one from amazon, which I am 50% convinced is a fake unless curt makes really really cheap controllers) will tell me by blinking something, but I can't easily see it (I can reach it though) where it is mounted. Not 100% sure though since it seems to have no issue if the trailer is not present. Honestly I'm freaked out that I drove 5 hours and have no idea when this stupid thing fell off. From now on my immediate plan at least is to always have my driving lights on (good idea anyway) and just constantly check for my side markers in the mirrors. Still, seems like someone would have come up with a better and consistent design given how seriously important lights, turn signals, and brakes are for anyone hauling.
The smaller opening on the right in your photo clearly shows a sonalert signal device. I can't tell from the photos how it's being powered though. I do see what appear to be diodes connected from the white ground to the green and red terminals. Given that the red is +12V and the green is the backup lights, I'd say that's pretty conclusive. There might be a couple of contacts that connect the sonalert when the adapter is assembled if there are no wires that we can't see in the photo. Below is a photo of the Reese version that might be closer to what you have.
 

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I am going to guess that this manufacturer also made the same alert device and just re-used the same housing. It makes sense and looks exactly the same from the outside. But there are absolutely no wires (if you can tell from the first photo) that go to the lower area at all. I have also seen the same plug in searches that has a 12v cigarette type outlet. So they probably just have a generic housing for everything.

Backup lights would also have a wire connected to the center pin (I still don't understand why center is backup and not something more logical like ground or even aux) and this does not.

Again, I appreciate the help, this has lead me in the right direction, even if that direction is that this is crazy. I'm going to do some testing hopefully on my lunch break and report back in case it helps anyone in the future. Or I may be the only one with this mysterious thing.

I appreciate the suggestion to post on airstream forums as well, although given the age of this unit (2016) I think they have all been standardized. I know wiring was weird on much older units and people usually just re-wire them for sanity. But you never know, as much as I like this camper it still certainly has its quirks and stupid design issues.
 

NY_Dutch

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I am going to guess that this manufacturer also made the same alert device and just re-used the same housing. It makes sense and looks exactly the same from the outside. But there are absolutely no wires (if you can tell from the first photo) that go to the lower area at all. I have also seen the same plug in searches that has a 12v cigarette type outlet. So they probably just have a generic housing for everything.

Backup lights would also have a wire connected to the center pin (I still don't understand why center is backup and not something more logical like ground or even aux) and this does not.

Again, I appreciate the help, this has lead me in the right direction, even if that direction is that this is crazy. I'm going to do some testing hopefully on my lunch break and report back in case it helps anyone in the future. Or I may be the only one with this mysterious thing.

I appreciate the suggestion to post on airstream forums as well, although given the age of this unit (2016) I think they have all been standardized. I know wiring was weird on much older units and people usually just re-wire them for sanity. But you never know, as much as I like this camper it still certainly has its quirks and stupid design issues.
You could try plugging it in to see what happens. Assuming your tow vehicle has the backup light connection wired, it should beep in reverse. Otherwise, it makes no sense at all that they would use an obvious sonalert and not connect it to anything. What other purpose would the device serve then since you've said there's nothing wired to it.
 
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Well, anti-climatic but it doesn't do anything useful. My best guess is what CharlesinGA said and someone must have had a 7-pin connector that did NOT send power to the brake lights and turn signals separately. Those are the only wires connected, and with what I assume are diodes inline. And given it doesn't have a brand, model, or anything else it must have been something cheap the previous non-technical owner must have been convinced of, or their tow vehicle had weird wiring although I swear he said it was also a similar year make.

Anyway, I certainly appreciate all the insight from everyone and learned something new, so thats always good. And I learned that I hopefully don't have to carry this stupid thing around anymore :)

Thanks again. I'll post an update if anything changes, but after a bunch of light tests and everything I'm pretty convinced this piece has no real relevance to my camper or tow vehicle and it'll live out its years on a shelf in my barn, or a landfill :p
 
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