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This multi-function, vehicle-end connector converts any 4-way flat, vehicle-end plug to a combination 7-way outlet and 4-pole flat outlet.
Features:
Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.
Hi there, towing enthusiasts. Today, we're going to be taking a look at Curt's 4-way Adapter to 7-Way and 4-Way with Test Light. As you can see here, our trailer has a 7-way connector but our vehicle used to only have a 4-way connector. With this adapter, we are able to break it out and have a 4-way and a 7-way so we can fit our plug in, because without it it's like trying to fit a round peg in a square hole.When comparing this to other similar adapters, the things that I like about this one over those is that it has both the 7-way and the 4-way. Some are just an adapter at the back that will allow you to plug your 4-way into it, giving you a 7-way, but then you lose the functionality of your 4-way unless you we're to unplug it from your 7-way each time. I love having this breakout for your various accessories that you may use.Another feature that really stands out is the tester that's included in it.
This is a great thing to have on hand, because often whenever you have an issue with your trailer, it always seems to be like when you're out on vacation, and why spend time having to go to a shop to get it fixed when you can have a tester right here and you can immediately tell if the fault is with your vehicle side or your trailer side for a quick easy diagnosis so you can get that problem fixed and get back on the road.If you have an existing 4-way connector on your vehicle, this adapter will attach and it'll plug right into your 4-way connection. It'll break that out into a 4-way that you can still access, so if you have accessories that use a 4-way, you're not losing your 4-way, but you are gaining a 7-way. By plugging your 4-way into the connection at the back of this connector, it'll take all those 4-way connections and put it out here in your 7-way giving, you all your necessary lighting, which includes your left turn signal, right turn signal, tail lamps, and brake lamps.We've now plugged in our trailer's 7-way connector into the connection in the back of our vehicle and here you can see our lights are operating on our trailer through that 7-pole connection. This'll keep us safe and legal when using our trailer is and it allows everybody behind us to know our intentions when driving down the road because they can see all of our lighting signals.Now if you we're intending on using a larger trailer that may have had breaks on it or additional accessories such as a power jack, you may need some additional connections here at your 7-way. There are breakout wires for those remaining connections and you can wire those up as well.Of the three remaining connections, one of them will be for your brake signal, which is the output for a brake controller, so you can then add a brake controller.
Next, it also has a charge line cable, which is your 12-volt, so you can charge a battery on your trailer or operate a tongue jack. Lastly is your reverse light circuit, which you can tap into the vehicle, so whenever you backed up on your vehicle, those reverse lights will also illuminate on your trailer.When not in use, our 7-way campus spring loaded, which will help it shut and there is a rubber gasket on the inside which will keep out any moisture, ensuring a long lasting connection. There's also a dust for our 4-way. This one is manual, it's not spring loaded, but it does function similarly, keeping out moisture to ensure long life on that connector as well.Now that we've gone over some of the features of our connector here, let's go over how you would install it on a vehicle that has an existing 4-way and give you some tips and pointers on how to get it completely set up for a full 7-way connection.A mounting bracket does come included with your 7-way adapter. Hardware also comes included to get it mounted up.
You can attach this to the bottom of your hitch, to the bottom of your bumper, wherever you'd like. We're using a no-drill bracket, and this will allow us to secure our bracket to our hitch without having to drill into it, which is nice because you won't chip the paint or anything and you don't have to worry about corrosion occurring at those drilling points. From there, our bracket that came with our adapter bolts directly to this no-drill bracket. If you need a no-drill bracket and you don't want to drill to get the bracket that comes included with it installed, you can pick up these no-drill brackets here at etrailer.com.You're going to be using this just to take your lighting from the your existing 4-pole connector so you can use it with the 7-pole. All you have to simply do is plug it into the harness that's coming out of the back.
We plugged our factory 4-pole into the 4-pole off of our new harness and then take the white wire coming out of our harness and use the included self-tapping screw to connect it to your frame or anywhere that's metal and grounded. If you're just using it for your lights, you're all done. These three wires don't need to be connected and we'll have all of our lighting signals at our 7-way, as well as the 4-way, located easily and conveniently at the back of the vehicle.The backup white wire, you can simply tap into the backup lights on your vehicle and then it'll send those signals out to your 7-way. For getting a brake controller set up with your charge line, I would recommend the universal wiring kit for brake controllers. You can pick it up here etrailer.com by using part number 5506. This will come with all the wiring, circuit breakers, butt connectors, and ring terminals you'll need to hook up a brake controller and the remaining wires from our 7-way connector here to the rest of the vehicle.Once you've got it all hooked up, we can test it out to make sure that everything's working using the included tester on the side of our 7-pole connector here. You want to make sure you have your left turn signal, right turn signal, tail lamps, and brake lamps.That completes our look at Curt's 4-Way Adapter to a 7-Way and 4-Way with Test Light.
Customer Satisfaction Score:
98% were satisfied with this product
2% of customers were not satisfied
Ratings & Reviews
I installed this 4 to 7pin adapter with the T-one harness 118449 and the Drawtite hitch on my 2016 Toyota Highlander. I think the install was 1st rate. This adapter allows me to connect either a 4 pin or 7 pin plug. Nice. Very simple to check out the installation with the test lights. Adapter looks rugged and well made. The 4 pin receptacle that slides into the bracket should have better retention though.
Also I provided a picture of the 4 wire cable from the car harness to the adapter as it exits the storage compartment. I removed the grommet/seal. Made an X cut in the center. Forced the cable through it. Made a waterproof seal with RTV.
I really liked the idea of having the LEDs to let me know if I was having any problems with the wiring harness, but I did find a problem with it. I installed the wiring harness myself, using the instructions on the website, but after connecting everything I realized that the LED for 12v power is always on. It is not switched by the key, so although an LED should have low draw, this might not be a good idea on a work truck that stays parked for long stretches.
My new Curt 4 pole to 7 pole and 4 pole adapter (C57674) with test lamps is a quality addition to compliment my Curt class III hitch. Attaching it to my '01 Blazer went smoothly, and testing to see that it was wired properly was a snap with the built in test lamps.
Norm M.
4/30/2014
No trouble installing. Works perfectly, except the 4 wire connector likes to come adrift, I like it very much even with that little glitch !
The directions were clear and the adapter performed well the first time I hooked it up. I am extremely happy with the product as well as the vast amount of resources provided by eTrailer that make self-installation by a novice such as myself less painful.
It is now one year later and I recently had a wiring issue with my trailer and the built-in diagnostic lights saved a lot of extra steps in diagnosis.
David W.
7/21/2017
Great! No problems! Glad I got it from etrailer.com
Great product I used this to convert my 4-way harness to a 7-way + 4-way harness on my 2011 Toyota Sienna.
Everything went really well. The only very small complaint I had about this product is the length of the white ground wire. It was too short to reach a good grounding point on the frame so I had to go buy some extra wire and connectors to extend it. Make that cable about 3 ft longer, and just provide the ring terminal and this would be a perfect product.
Installing it makes me want to splurge on a tow controller and charge line...
Aldo
6/27/2014
HiI have a toyota sienna 2011 and i want to tow a pop-up camper. Mine has a towing package. The camper is around 2400 lb. in your case do you think a brake controller is necesary?can you tell me What kind of cable do u buy to extend the white ground cable?Di d u buy the no drill tie bracket?
Daniel S.
6/30/2014
Aldo. We towed a popup trailer that was little less than that loaded weight without any issue. This was a one time rental for us. We towed up over Vail Pass in Colorado without any issue at all. The engine and transmission on the Sienna could tow a lot more weight, it is limited due to the suspensiontire rating.The only problem we faced is that when hitched we couldnt open the rear door of the sienna due to the trailer jack on the tongue of the trailer.If I was to tow regularly I would invest in a break controller, charge line, and a Weight Distributing Hitch. The main limitation in towing with a sienna is the hitch weight.No I didnt buy the tie bracket. The hitch I purchased 75696 had a built in bracket that this fit on perfectly just had to get a few screws/nuts for it.I just bought some 12 guauge auto wire at autozone.
Great product for a great price, it's worth mentioning though that the 7 blade and 4 blade conections don't mount side by side unless you use the supplied bracket, mounting it through a flat spot on the bumper Wil leave the 4 pin connector hanging behind where you still have to crawl underneath to hook up a small trailer. But the LED lights are absolutely awesome to have and have labled.
Daniel
10/22/2017
Still works great, and the led lights are still the best feature
I was surprised at how sturdy this installation is. etrailer sure helped me out along the way with this installation. Special thanks to Alex J for his help on several occasions to help me get the right hitch and accessories for my new 2021 Hyundai Palisade Calligraphy.
Install was simple. Plugs in, added my own wires for brake controller and constant 12v. Works 99% great. When trailer is hooked up up, works perfect. Except, when I I unplug the trailer the test lights mess with my brake controller. The LED somehow is still inline with the circuit, well because it is a test light. I snip my blue wire going into the harness and my brake controller works perfectly when I unplug it. Have to switch over to the same adapter harness that does not have the test lights.
I am using a redarc tow pro v2. I get the flashing red light about 10 seconds after disconnecting the plug. In my case the error list this as a faulty ground on the trailer. I don't get it because it is unhooked? Regardless I wired the controller and adapter harness ground all the way to the battery itself. Still didn't change a thing. I even called redarc tech support in Australia. I never did tell them about the test LED's though, maybe if I did they would have went a different direction with the diag. They helped the best they could. I don't fault the person I talked to at all. I would guess the test lights on the adapter to be wired in parallel to work. With that thought, after unplugging the trailer, the brake controller must still be seeing the LED test light. I'm not an electrician/engineer but the small led of a test light, maybe not enough resistance overall to think a trailer was hooked up, but enough to throw a fault. If I was to break/damage the test led for brake, I would bet that it would most likely would work fine as it would cause an open in the circuit.
Jenny N.
11/1/2021
Thank you for your feedback. We had heard of this happening with the adapter and reached out. There has been a design change with the adapter to eliminate this issue.
Jerry
10/18/2022
Apadter works great sitting on my shelf. Installed the same style adapter that doesnt have test lights. Brake contoller works as designed.
I bought this for my '68 GMC 3/4 ton, which is in really nice shape so I wanted a clean install. The hitch was pretty easy to fit - I had to drill holes in the frame but I knew that going in. I especially liked the built-in bracket for mounting the trailer plug, worked great with a Curt combo 7 pin / 4 pin adapter from eTrailer.
Good product, great seller.
Shipped out very fast and arrived before the estimated arrival date.. install was super easy with the LED test lights.
Great customer service on-time delivery super fast shipping product was just as described works well and just what I was looking for.
Great product! Sturdy and weather-proof connections and wires! Easily installed. Thanks Curt and etrailer.com for an awesome item!
I need the ability to pull trailers with both 4 Pole and 7 Pole connections and this adapter did the trick. It's heavy duty and I think the extra few bucks for the Test Lamps was well worth it.
Ordering was easy, good price and quality of part. Part arrived on time. Will definitely be Ordering again.
Last project built. Used etrailer for almost all parts, including the 7 pin wiring harness. Friend wants one now so started another one. I will be getting all the parts from etrailer...
Very quality product. Well built and easy to install. Had another manufacture's harness on my vehicle and after about a year, it was intermittent. The Curt harness is sealed in the back which is why I choose this one along with the builtin test lights. I would recommend this harness to anyone along with the great service at etrailer! I installed the harness on a 2016 Hyundai Santa Fe Ultimate.
Installed and have camped for one season using this 7-pin connector. Works great. I did make one mistake, I didn't add a relay to break the aux power connection when my vehicle is not running so the aux power LED is always lit. Got a number of comments about that this season. Might have to add a relay...
Very easy install. My truck had a precut hole in the bumper for the plug. I then hooked the spare 4 pole plug into a Reese Universal mounting bracket and mounted it onto the hitch.
I use both 4 pole flat and 7 pole connections on our trailers so this fit the bill. Here, I welded a bracket to use it on our Dodge Journey.
This is the second vehicle I have installed this adapter on. We tow a Coleman popup and another smaller trailer so we need both the 4-pin and 7-pin adapters. The test lamps are great to confirm that you have installed the wiring correctly.
The bracket was too wide for the OEM hitch and cover on a 2013 Highlander (see photo). I had to grind down part of the the bracket so it would clear the plastic cover. The top two mounting screws did not line up. I had to elongate one of the holes. The 4 pin connector merely slides into the side of the bracket, rather than fitting in like a grommet, so I'll bet it comes out one day. The wiring on the back of the 4 pin connector is visible when looking at the side of the bracket, making for a less than clean look.
Excellent kit. Plugs right into the taillights without messy crimping and cutting. Install was less than an hour.
Perfect . My new Subaru hitch has a flat plate to which the dealership attaché the 4-flat. I used “2 L-brackets” to accommodate the 90 degree bend of the adapter bracket.
Randall J.
9/4/2024
Another feature i like is the red light on the device which helps me locare and identify my vehicle day or night.
I recently had a receiver hitch installed on my 89 Silverado and the wiring was merely zip tied to the safety chain connection. Well that didn't sit well with me. I wanted a more permanent wiring connection point. So I purchased your 4 flat to 4 flat and 7 way plug and installed it. So far so good. The installation turned out perfect and it looks good. The test lights are a great thing as well. I couldn't be happier.
Lawrence L.
8/16/2018
Perfect. The only issue I had was the 4 flat didn’t stay in the bracket but that was easily remedied with a couple of holes and some safety wire. Other than that I’d say u have one of the best setups you could ask for.
The videos from etrailer really made the installation of a trailer hitch, 4-pole adapter, and 7-pole adapter with test lamps a relatively painless procedure. I now have my 2019 Highlander equipped for towing small campers and trailers and the test lamps on the C57674 adapter ensure I’ve hooked up everything correctly.
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Chris H.
5/19/2014
I am still very happy with this adaptor, but I did put back in the plug on my brake controller so I could unplug it when the trailer was not connected, the brake light was on, and I disconnected the continuous 12v. Also, make sure your 4 wire connector is clean or you might have dim lights. Although the LEDs are useful, I found a plug in tester to be more accurate because of the false brake signal I was getting.