Any advantage to hooking up 7pin vs 4pin?

[lfkwtz]

Just got my first trailer and my 4runner has both a 7pin and 4pin on the hitch. My Casita has a 7pin cable that's a little short - so the seller recommended I get an extension cable for it (about $20).

But then I saw this adaptor for $5:
https://smile.amazon.com/57240-7-Way...s%2C196&sr=8-8

My thought would be that this is cheaper AND maybe more universal? (in case my 4runner dies or something, I believe 4pins are a bit more common on towing hitches - right?)

Any reason I shouldn't go for the 4pin approach?

[Mary F]

The 7pin sends power to your brakes and has a charging line for your house battery.

The 4pin connector is for a boat (or utility) trailer (tail lights and blinkers only).

Does your 4-Runner have a brake controller?

[Raspy]

The seven pin is much better. As Mary indicated, it has a charging wire and a brake wire. And since the trailer is already wired for a seven pin, that is the thing to use.

[John in Santa Cruz]

rather than an extension which would have twice as many connections and hence be half as reliable, I would get a longer pigtail and replace the entire cable.

these come in various lengths, https://www.etrailer.com/Wiring/etrailer/e99011.html

your Casita probably has a bunch of random connections done rather poorly with crimp connectors, under the closet. ideally, you put this box there, and terminate the existing trailer-side wires with suitable ring terminals. alternately, you cut the existing cable somewhere around the A frame, mount the terminal box on the inside of the a-frame, and ditto, terminate the existing wires with ring terminals and match them up...

[Casita Greg]

Casitas, (and most other travel trailers out there,) have legally required electric brakes. Not only are the trailer brakes a DOT requirement, but the required "break-away" connector is also a legal requirement, just like having a good functional working trailer battery, (which would power the electric brakes if the trailer were to come off the hitch.) You are required to have a break away pull-out switch, which will activate the trailers electric brakes in the event of the trailer becoming disconnected from the tow vehicle. Non negotiable. 4-Pin plugs DO NOT provide power to the brakes, or battery charging power to the trailer's on-board battery, which must also be hooked up when the trailer is being towed. A 4-Pin connector will not cut it, period. If you are ever involved in a traffic accident and any sharp attorney can decipher that you didn't have the right configuration, a good battery, and the proper wiring will have a field day suing you for everything you own. Just sayin'.

[John in Santa Cruz]

now, there *are* remote brake controllers that live on the trailer, only need a 4-wire light connection to the vehicle, and have an RF module on your dash for manual braking and monitoring. this setup will not charge your trailer battery while traveling.

huh, I know Tekonsha made one, but its no longer on their site, must be discontinued?!?

[gordon2]

Originally Posted by John in Santa Cruz

now, there *are* remote brake controllers that live on the trailer, only need a 4-wire light connection to the vehicle, ...

I believe they still need a line to the tug battery to supply power to the trailer brakes. (Autowbrake does) So a 4-way and one more would be the minimum. Thats five. Of course that does not include such dangerous and kludgy arrangements such as using the trailer battery for all (non-emergency) trailer brake power or trying to power the trailer brakes from a brake light. Picking up the brake signal at the light is one thing... supplying the power to the magnet is another.

And state laws vary. Absolute statements about the various state DOT requirements are likely not always going to be correct.

[stevebaz]

Originally Posted by John in Santa Cruz

now, there *are* remote brake controllers that live on the trailer, only need a 4-wire light connection to the vehicle, and have an RF module on your dash for manual braking and monitoring. this setup will not charge your trailer battery while traveling.

huh, I know Tekonsha made one, but its no longer on their site, must be discontinued?!?

I use the rf trailer bake controler. And it uses a 7 pin connection going in and going out of the controller.

[chrisblessing]

Originally Posted by Casita Greg

Casitas, (and most other travel trailers out there,) have legally required electric brakes. Not only are the trailer brakes a DOT requirement, but the required "break-away" connector is also a legal requirement, just like having a good functional working trailer battery, (which would power the electric brakes if the trailer were to come off the hitch.) You are required to have a break away pull-out switch, which will activate the trailers electric brakes in the event of the trailer becoming disconnected from the tow vehicle. Non negotiable. 4-Pin plugs DO NOT provide power to the brakes, or battery charging power to the trailer's on-board battery, which must also be hooked up when the trailer is being towed. A 4-Pin connector will not cut it, period. If you are ever involved in a traffic accident and any sharp attorney can decipher that you didn't have the right configuration, a good battery, and the proper wiring will have a field day suing you for everything you own. Just sayin'.

I live in Arizona. Under state law there is only a requirement for independent electric brakes and breakaway for trailers with a gross weight of over 3000 lbs and above. "Legal requirements" differ from state to state.

[Jann Todd]

Originally Posted by lfkwtz

Just got my first trailer and my 4runner has both a 7pin and 4pin on the hitch. My Casita has a 7pin cable that's a little short - so the seller recommended I get an extension cable for it (about $20).

But then I saw this adaptor for $5:
https://smile.amazon.com/57240-7-Way...s%2C196&sr=8-8

My thought would be that this is cheaper AND maybe more universal? (in case my 4runner dies or something, I believe 4pins are a bit more common on towing hitches - right?)

Any reason I shouldn't go for the 4pin approach?

7 pin only way to go. It charges the trailer battery, gives the brakes power and you do want brakes. Can you imagine going down a mountain with all the weight pushing you and your vehicle brakes trying to stop you. It would overheat your vehicle brakes-been there done that. It is not safe and in a lot of states the brakes are required. For a few bucks don't put your life at risk.

[John in Santa Cruz]

Originally Posted by chrisblessing

I live in Arizona. Under state law there is only a requirement for independent electric brakes and breakaway for trailers with a gross weight of over 3000 lbs and above. "Legal requirements" differ from state to state.

Casita 16 and 17's are both 3500 lbs GWR.

[chrisblessing]

I understand. I was simply pointing out that the legal requirement for electric brakes and breakaway mechanism does not necessarily apply to the many "...other travel trailers out there" and that requirements vary from state to state. That said, Casita Greg, you and many others on the forum convinced me to add electric brakes to my '13 Scamp. I just completed the wiring (7 pin) and will be testing and adjusting them today.

https://drivinglaws.aaa.com/tag/trailer-brakes/

[gordon2]

A number of people have definitely stated that using a 7 pin connector will result in your tow vehicle charging the trailer battery. This is not necessarily true. The charge line is sometimes not present or operational in the tow vehicle (along with the often unused back-up light connection). Its nice to have a charge line but it does run the risk of discharging your tow vehicle battery in some cases, for example if you run the fridge on 12 volts and do not manually or automatically disconnect the charge line when the vehicle is off for some time.

So even if you dont use a charge line, if you use brakes then use a 7 pin for camping trailers. Its a standard. But not all the pins will always be used.

For brake, running and turn signal lights on a trailer you need 4 wires. If lights are all you need, then a 4 pin is fine.

For electric brakes you need a fifth wire
For trailer battery charging from the tug you need a sixth wire
For backup lights on the trailer you need a seventh wire.

So for anything more than lights now days use the standard 7 pin even if you only use 5 or 6 pins.

[thrifty bill]

I find 7 pin more secure. So even on my old Trillium 1300 (no brakes), I installed a 7 pin plug.

[chrisblessing]

Originally Posted by gordon2

For electric brakes you need a fifth wire
For trailer battery charging from the tug you need a sixth wire
For backup lights on the trailer you need a seventh wire.

So for anything more than lights now days use the standard 7 pin even if you only use 5 or 6 pins.

I did exactly that. I'm only using 5 of the 7 available pins on a 7 pin connector. It's more secure, protected from the elements and aesthetically pleasing.

[Darwin Maring]

You can use an addapter in the 7 pin to tow a 4 pin unit"
You can not addapt a 4 pin unit to a 7 pin.
It allows your tow vehicle to tow other trailers.

[ZachO]

I always buy the vehicle-side 7 pin connector that has a 4 pin connector right next to it. That way I don't need a separate adaptor (which I've had fall out on bumpy roads, and realize miles later that the trailer wire was dragging on the ground and is destroyed) when I tow a "regular" trailer. Very convenient.

[Joe MacDonald]

nobody has mentioned the 5 pin connector now being used on a lot of Boat trailers with an electric over hydraulic braking system.

Just to muddy the waters............

[steve dunham]

Originally Posted by chrisblessing

I live in Arizona. Under state law there is only a requirement for independent electric brakes and breakaway for trailers with a gross weight of over 3000 lbs and above. "Legal requirements" differ from state to state.

What difference does that make ?
I was taught to do the right thing because it’s the right thing to do
I have brakes on my utility trailer not because of some law but because it’s just common sense .

[Reinout]

@lfkwtz Which 4runner do you have? If you have a 4th or 5th Gen 4runner although you have the 7 and 4 pin options, you will still need to connect a brake controller. With the weight of the trailer I would say it's a good option to "upgrade" to the 7-pin. It's nice with our 2007 4Runner to have the extra brakes AND it charges the battery in the trailer. It's not too daunting to hook up the brake controller. Talk to the folks at etrailer.com they set me up right.

I think others have mentioned this already but, go with 7 pin. It'll allow you to tow anything with 7 pin or 4 pin (with adapter) and use all the functions.