Most Popular 4 Flat for 1979 BMW 3 Series

Installed on a 2009 328i BMW, took more work to get interior panels off/on in trunk area than the wiring. I had the electrical wiring diagrams for the car which really helped.

This product works as expected. There is not too much to the installation, just plug it in properly and mount the ground wire. I did not find an easy way to mount this to my wife's Odyssey, or to the trailer hitch (item# 75270). Luckily, I do prototype design and manufacturing. So I came up with my own solution. I designed and made my own bracket to mount the 7 pole to the trailer hitch. It works like a charm, and looks great!

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i had to replace these two items as my dear daughter went down our goat path driveway too fast. they replaced the originals from etrailer from the prior year. shipping is timely and customer service actually helps! i wired from battery to controller to hitch myself, and everything fit.

Great build quality, but unfortunately it will not work to legally use a 4-pin trailer being towed by a 7-pin Euro/Land Rover plug. Its simply mapping 4 of the 7 pins to the following pins on the 4-pin side. Left running, Right running, Stop and negative, there is no provision for indicators or dual sided brake lights. It needs diodes (which it does not have) to do this. etrailer just needs to update the description as this is a good basis to make various adapters.

Received product in good order, well packaged, initial some delay, manufacturer was chased by etrailer, and earlier dispatched by manufacturer; delivery trail clear stated, very good. On receiving verified at UHAUL: connect with 1983 Land Rover (Defender) 110 Stationwagon (photo: rear, while on transport): all functioned ok. Apparently some diode(s) included, as the 7 pin has individual stop light which translates as left AND right indicator on flat pin. Emergency flashing (all indicators left and right) tested ok at UHAUL (connecting to trailer). LR has European homologated 3.5 metric Ton (7700 lbs) tow hook and has done some 60,000+ miles towing with current odometer reading 578,000+ km (on/about 360k miles)

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Replaced the wiring and lights on my 1992 boat trailer. I was able to get everything needed from etrailer. I think Optronics is of the highest quality and recommend both etrailer and Optronics product.

Works very well after re-wiring trailer lights with waterproof distribution box.

Just what I needed for my home-built bike carrier. My wife rides an e-tricycle and by the time I loaded the trike and a couple of bikes on this platform, you could not see the car's taillights or blinkers. This harness worked perfectly!

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Wiring worked perfect for my project. I replaced the wiring on my 14 foot utility trailer. If I was to do it again I would buy the next length up. I would have liked to have a little extra wiring if I was to ever need it.

I wanted one with a LED tester built into it to "trick" my SUV into thinking I had a trailer connected when really it was just a bike rack so the car didn't slam in it's brakes while reversing thinking it was something else. So I bought a different adapter. The picture slightly deceived me into thinking this had LED tester because the plug is attached by a rubber string (that I thought was a wire). So add another picture of the other side and that would eliminate my confusion. 4 stars because it probably works the way 99% of people would want to use it for.

Everything worked out well. On time and fits perfect. Attach hitch setup and my new Ridgeline. It comes with a 2" inch receiver and I have a full compliment of 1.25. stuff from my previous car. All from etrailer i must admit! so I needed the 2-1.25 reducer, a good lock, and the 7-4 reducer for my goodies! Thanks for the grest service

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Not too difficult to install, but I would recommend using a car lift so you don't have to work from your back (review includes wiring harness and Brake Controller)

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.

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Works fine. Reasonable price. I'm happy that etrailer is around.

Thanks for the follow up!

Great product no issues at all. Product as described & fit properly.

Pretty straight forward. I used it to switch my European trailer's connection to be able to connect to my Wrangler's 4-pin trailer hookup. No issues. works great.

Installed the Hopkins muti-tow 7, 5, and 4 way flat connector this morning. I ripped the original connector that was attached to the bottom of the hitch receiver off when I was 4-wheeling into the Doll House campgrounds in the Maze District of Canyonlands a month ago. So, I cut a hole in the bumper and mounted the new Hopkins connector, cut off the old broken connector mounting bracket, and connected the factory wiring to the new Hopkins device. Hopkins product installed easily, looks great, is now out of the way, and has the flexibility of multiple trailer connectors when required. I am pleased with the product. Attached is a photo.

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Exactly what we had been looking for. Now I can hook up multiple trailers with different connectors and all the electrics on each trailer works. I mounted mine directly to the receiver hitch frame. The biggest challenge for us was routing the backup wire from the taillight housing, through the body of the truck to the connector. the rest went together fairly easily. Seems to be pretty solid and looks much better than the loose pigtail connector it replaced.

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GREAT ACCURATE REPLACEMENT WIRING.

Timely shipment. I’ve bought from your company before and haven’t been disappointed. Nice job.

Really quality piece. Plenty of length to connect back to the rest of my utility trailer wiring that was still in good shape since it was in an area subject to far less abuse. Nothing worse than having to fix the corroded wires in between replacing the worn out plug every few years. This should give me years maintenance free service even with the toll winter takes.

This is the 2nd one of these I have purchased. They are a good product (therefore the 2nd purchase) but have a few areas that could be improved. 1) In cold northern winters (MN -10 F), the cable gets very stiff, because of the lack of flex, my trailer connection pulled out when turning, dragged on the ground and ground down the plug. 2) the connection where the cable jacket meets the plug separated (again, due to cold weather?). Even though I would prefer a more temperature-forgiving flexible cable, I believe this design is better than the other 4-flat trailer-end wiring harnesses currently available. I also purchased a Hopkins Endurance Quick-Fix Replacement 4-Way Flat Trailer Connector w LED Test Lights - Trailer End to as a quick fix to this cable to temporarily fix my trailer wiring until permanent repairs can be done.

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I used this harness to rewire a 10ft vintage RV. There was plenty of length to reach the rear lights. I used Scotch Locks to tap into the wiring for the side running lights. Very good product.

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Very happy with every aspect of my order. Received product and quality appears to be outstanding. I’m especially impressed at the instructions made available to install the wiring harness, written with the product and link for video. All bases covered and follow up to make sure all goes well. Am confident of their assistance should I need it.

Very strong wire on the connector. Finger hole access is priceless!

Good quality and fast shipment. The hole makes it easy to disconnect without straining the cables.

Perfect! extra long so I got rid of all my bull crab wiring

Well made, especially the mounding around the plug. Pin alignment was very good.

I used the Hopkins 3 to 2 converter to make a 6-pin round to 4-flat connector for my Winnebago View motorhome. While there are 6-4 plugs available to do this, they do not work on the Winnebago View (no brake lights). This adaptor works great.

This device was no help in connecting my five wire trailer to my four wire goldwing. I ended up having to use a number of diodes in the trailer wiring to make everything work properly. My trailer had red LEDs that were used for Brake, Turn & stop and I had to get the brake and turn function to share the same lead on the light fixture.

I just installed this on my 2015 Volvo XC70. I also used the Curt XC70 plug and Play for wire kit. I watch two of etrailers excellent insulation videos. Installing the hitch and both the wiring products took me around 3.5 hours. I think Curt products are great and they are reasonably priced! e-Trailer makes your DIY installations easy. You just need to take your time when removing interior panels and double check your work. I used Volvo's torque specs for the bumper parts when I installed the hitch. E-trailer doesn't stop with just hitches and wiring solutions, they have just about anything you need to load and haul overhead or behind safely. What about performance? E-trailers got you covered. If you get in a jam during the insulation, don't fret or worry, call the text at e-trailer and they'll walk you through it. I want to thank E trailer and their professional staff for helping me with my truck and auto towing and lighting solution for over 10 years now!

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This was/is a critical piece of any towing system, and as such requires extra care to hook up properly . I would recommend testing each connection as you hook it up being extra careful to make sure you are matching the terminals in the mating connector properly. This harness/connector performs perfectly when properly installed.

I ordered this wiring kit for a 2003 Dodge Ram 1500 I recently acquired. The Ram was not tow ready but did have a factory 4-way. I also ordered hitch #13333. The wiring kit is very high quality and was easy to install. The 7-way fit perfectly where the factory 7-way would have gone. I'm using a Tekonsha Prodigy RF wireless brake controller so the blue lead was not needed but I left some extra should that change. Thanks etrailer!

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Arrived on time and installing now