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Curt LED 4-Way Flat Connector (Vehicle End) Tester

Curt LED 4-Way Flat Connector (Vehicle End) Tester

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Curt LED 4-Way Flat Connector Tester

This circuit tester plugs into the four-way trailer connector on the vehicle. The bright LED lights analyze the trailer connections and indicate which functions (tail, left turn and stop, right turn and stop) are working properly and which are not.



58260 Curt LED 4-Way Flat Connector (Vehicle End) Tester

Item # I26





Video of Curt LED 4-Way Flat Connector (Vehicle End) Tester

Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Curt LED 4-Way Flat Connector Vehicle End Tester Review

Hey everybody, Ryan here at etrailer. Today, we're going to be taking a look at the Curt four-pole vehicle side trailer, wiring tester. So, if you guys have ever towed a trailer before I'm sure you have encountered this problem. You get all hooked up, and kind of do a walk around, you know you kind of do a pre-trip before you hit the road. You check a few things out, one of them being the lights. And, of course, you turn your blinkers on.

Maybe you have a light out at the trailer. You hit the brakes or the tail lights and something's wrong. And then this kind of turns into a headache. You know, you're, you're checking your vehicle side, checking fuses, making sure everything's good there. Then, you get the going on the trailer side.

It's kind of just a big mess. And one thing you can do to isolate that problem is use a vehicle side tester like this. So, the way this is going to work, is it's going to plug into your vehicles four way flat connector. All right, and then that's going to isolate the problem. So, once you plug this in, you can run through all of your signals and your lighting functions.

And if they all work back here, then you know, okay something's going on with my trailer and you can focus your time on that. If you don't have all your functions back here chances are good. You could say, okay, trailer's probably okay. I probably have an issue with my vehicle side and you can focus your energy there. So, at the end of the day, if you do have an issue, it's a great little tool that can potentially save you a ton of energy.

So, whenever you are plugged in to your vehicle side, you can test the function. So we're going to have our left turn signal, our right turn signal, our taillights, and our brakes. So, since these lights are LEDs, really easy to see, even on a sunny day like today, which is convenient, especially if you're by yourself, kind of trying to, you know if you have miring stored inside you can hold it up or mount it up and check it while you're in the driver's seat, so you ain't got to get out of the car every time. But, since we don't have any labels or anything here, I figured it'd be useful to share what lighting function illuminates the light on the test, or if that makes sense. So, this light here should turn on when you use your right turn signal, the one next to it should turn on when you use your left turn signal, both of these lights should illuminate when you apply the brakes, and this one should come on whenever you have on your tail lights. So, let's say if you're, you know, testing your, your right turn signal, this one should be flashing. See, this one isn't, but this one is, okay So, you're still getting something to happen, but on the wrong circuit. So, that could help kind of direct you as well to get it figured out. You may have a short or something like that in the electrical system, and that could be looked at. So, when it comes to this tester, honestly, this is probably the last one you'll ever need, unless you lose it or something like that. Things are actually pretty, pretty stout. They're pretty solid. These are actually the exact ones we use here at the shop. And we use them day in and day out, all the time, and we've had them for years. They still work like they should every day and they really take a beating, and they just continue to work. So, for the average person to use them, occasionally, I mean this should last for the life of your vehicle or the life of your trailer, and then some. So, really nice, you know, it does have a key ring holder on the top there. And what we do, here at the shop, is usually put a zip tie or some type of key chain on there just to make a little larger so we can hang it up. If I had, you know, if I was going to keep one in my personal vehicle, something like that, you know, I'd probably end up using a key chain with my trailer lock and everything else on it, throw it in the glove box, so you always have it. So, it's a little nice touch and something I thought was worth mentioning. So, as I mentioned, this could work for your four way flat type connectors and it just plugs right in, just how you'd plug into the trailer side. And if you have multiple vehicles or different trailers, things like that and you need a different type of tester, not a big deal. We offer other ones as well. Whether you have a five way or a round seven-pole something like that. There's going to be a tester similar to this available here. That way you can use it for that wiring as well. And that'll finish up our look at of the Curt four way flat trailer, wiring tester..


Customer Reviews

Curt LED 4-Way Flat Connector (Vehicle End) Tester - I26

Average Customer Rating:  4.9 out of 5 stars   (959 Customer Reviews)


- I26
by:

Works great to verify wiring from the vehicle end. Confirmation and peace of mind you connected everything correctly and the unit/harness you purchased isn't doa! Also will be useful in the future to trouble shoot any issues.



- I26
by:

Since the T-One wiring harness came with a plug that could only fit on way on the Subaru plug, this is really just plug and play. So ... probably did not need this but it was nice to be able to confirm that everything was working as it should and, good to have for the future in case something goes awry or one purchases a different vehicle.



- I26
by:

It really helped to have a detailed installation video available on your site, helped me to order the correct wiring harness and know that I can reach out to you with any questions!



- I26
by:

This simple device proved to be a great way to ensure that the trailer hitch wiring was installed correctly and ready to go. We rented a U-Haul, and all worked as expected.



- I26
by:

Trailer Hitch came in only a few days and was really happy to be able to review the installation video before I purchased. You offer a great service and appreciate the help.



- I26
by:

This is a great affordable tool to check wiring harnesses. Works great.



- I26
by:

LEDs are bright and generally it's nice to have a tester when trailers start having wiring problems so you know it's not the truck!



- I26
by:

VERY HELPFULL TOOL FOR CHECKING CONNECT IONS.


Comments
VERY SATISFIED. HANDY TOOL.
Tom - 05/05/2022


- I26
by:

Handy little tool that confirms wiring easily. I like that I can position it so I can check the brake light circuit without assistance. (Open the hatch and prop it up so I can turn and see it).



- I26
by:

Takes all the guesswork out of connections. Etrailer is definitely the company to deal with. Quick and friendly service.



- I26
by:

This little connector is a lifesaver for a first-timer installer of the 4-pin trailer harness. You need to have the ignition on for this connector to work, you don't have to have your car turned on though. It looks very well built and I like the fact that the LED lights are covered and protected. Not much to do with it once you've tested your trailer harness, but it's one of those tools that it's best to have than not.


Comments
Well, I havent used it since that first time. This product to me is a one-time use. But I still have it and have no plans of reselling it or whatever, I dont know when Im going to need it again so its best to just keep it in a safe place.
Ricardo Z - 08/17/2021


- I26
by:

Great value (few bucks) and very handy. A must have for checking your new install (beats moving a trailer and vehicle around and eliminates questions of defective trailer lights when checking wiring). Frankly I believe every new wiring harness package should come with one.



- I26
by:

Useful for testing vehicle wiring.



- I26
by:

Just what I needed to be sure trailer lights are wired properly. I'm in Florida now, trailer is in Ohio. Put hitch and wiring harness on new 2020 SUV, but won't be back to Ohio for a couple weeks. Nice to know that everything is ready while I have car dismantled. Low price, fast delivery. Thanks


Comments
Perfect. Easy access, plugs right in,has rubber cap to keep weather out of plugs.
Craig - 05/16/2021


- I26
by:

My experience with etrailer was nothing but phenomenal. The site was easy to use and supplied all of the technical information I required as a first time user. I am not a vehicle savvy person, but the instructional videos made me feel like one. All of the items that I purchased were exactly the quality that I was hoping for. Their customer service is excellent as well. I recommend etrailer to anyone that is in need of such any item they offer and will be using them again!



- I26
by:

Works great to test out your wiring.


Comments
Still a nice little gadget.
Jim - 04/30/2022


- I26
by:

Product arrived and did not work


Comments
You mentioned that it arrived and did not work. Did it work on any of the signals? Do you still have the tester?
-- Etrailer Expert Jenny N - 05/04/2022

Comments
It worked for every signal except left turn. I tried it in three different trailer hookups that we have and all three had left blinkers that worked so the unit was defective. I do not still have the unit. Thanks for asking
-- comment by: John - 05/04/2022


- I26
by:

I decided I would like to have one of these testers on 5/20 and it was in my mailbox on 5/23. It was very easy to purchase and it does exactly what they say it will do. I am very happy with etrailer.com and have used them on several occasions in the last several years. I even had to return a product recently and they took care of it quickly with no hassle. Overall I believe they are an excellent organization that I have total confidence will be there for their customers. Their videos about their products is just a plus and are very factual and correct in how to deal with their products.


Comments
Excellent
Dan R - 05/26/2021


- I26
by:

Still working great


Comments
Great still looking good
Jose - 05/04/2022


- I26
by:

It has performed as it should. The video instructions were a great help. Thanks



- I26
by:

I bought the wiring harness to use on my boat trailer. but since then I have used it on a number of trailers. I have let some friends use it for there trailers also.



- I26
by: 06/01/2021

Exactly what I needed to rewire a 20-year-old trailer that was starting to show it's age with inconsistent lighting performance and continuity issues. In addition to purchasing this lighting harness, I upgraded all my incandescent bulb side markers and taillights with LED units and complete rewired the trailer. etrailer had everything I needed in one place with excellent pricing and superb service. Everything is working great and I love the brightness and visibility of the LED lights.



- I26
by:

A Must Have. Spend a couple bucks to have a way to check the plug, at installation and any time in the future. The ‘icing on the cake’ when you are purchasing/installing a hitch and electric cable assembly.



- I26
by:

I had placed an order from etrailer for a trailer wiring kit, as I'm going to be renting a uhaul trailer to move some stuff. The wiring kit looked fairly easy to install (based on a video on etrailer), but it then occurred to me that I wouldn't know if I installed it correctly until I picked up the rental trailer, and then it would be too late to do anything about it. So I looked at various testing tools and this looked like the easiest (and cheapest). It worked exactly as promised. (Turned out I installed the wiring kit correctly.) My only suggestion is that there should be a tag (or label, etc) on the tester indicating what light should light up for what function. I know the etrailer website shows which light is for which function (ie brakes, lights, turn signals), but it would make sense to enclose this info with the device. That said, this was easy to use and did exactly what it should.


Comments
The wiring kit I bought continues to work just fine. Im also glad to have purchased the small wiring tester at the time - the first time I rented a trailer the lights werent working without the tester, I would have assumed the problem had to do with the installation of the new wiring, but this gave me the confidence to know the problem was with the rented trailer and I could insist they come and fix it which they did.Anyway, still very pleased with the purchase, and would continue to recommend it.
BJB - 07/20/2015



- I26
by:

Pretty easy to install with the instructions correct. Have not had the opportunity to try it out on a trailer yet (change of plans).


26
960
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Ask the Experts about this CURT Electrical Tools



  • What are the Different Circuits on a 4-Way
    The jacketed circuit is the ground. The one right next to that one is the tail light circuit, next to that one is the left turn circuit. And then the last one on the end is the right turn circuit. Check out the picture I attached to see the circuits labeled. I attached an FAQ article on trailer wiring that you might find informative also.
    view full answer...
    Image 1 for
  • Why Would Circuits of the I26 Partially Glow When No Trailer Wiring Circuits are Activated
    It sounds like your trailer wiring setup is fine. The thing about LEDs (like what the # I26 has), is that they require such a tiny amount of amperage to partially illuminate that when they are used in trailer wiring situations they can partially glow like you described if there is any amperage at all bleeding out of the circuit. What I would do is connect the 4-way of your 2014 Ford Explorer up to a trailer and see if it functions properly. If it checks out then you would be good to go.
    view full answer...
  • Which Lights will Illuminate on the Tester # I26 When Brakes are Applied
    When your brake lights are pressed and you are using the # I26 as a tester the two pins opposite of the jacketed (ground) pin will illuminate. These are the left and right turn/brake light circuits.
    view full answer...
    Image 1 for
  • What are the Functions of the Lights for Trailer Wiring 4 Pole Flat LED Tester # I26
    From left to right the first light tests running lights, the middle light tests left turn and brake lights, and the last light tests right turn and brake lights. On a 4-Way flat vehicle connector, the one exposed pin is the ground, next to that is running lights, then left turn and brake, and the last pin is right turn and brake.
    view full answer...
    Image 1 for
  • Troubleshooting Vehicle-Side Trailer Connector Right Turn Signal Staying On
    If you are putting a test light like the Curt # I26 on your vehicle-side 4-Way then you may have installed your vehicle-side 4-Way incorrectly. Is your running light indicator blinking when you put your right turn signal on? If this is the case then you simply need to swap out the wires for your right hand and running lights (see attached photo). Another possibility is that you have a bad ground or your vehicle connector is full of corrosion. Check both of these while you are at it and...
    view full answer...
    Image 1 for
  • Will Wiring Harness # 118534 Work with Power Lead Disconnected or Damaged?
    The T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector # 118534 will not function without the power lead. It may function with a slightly damaged power lead, so I recommend using a tester like # I26 to test your wiring functions and simply visually inspect your power wire to your battery.
    view full answer...
  • No Trailer Lights on a 2018 Honda Pilot with Tekonsha 7-Way Harness Part # 118760
    What type of tester are you using? If it is one like the Curt LED 4-Way Flat Connector part # I26 then that may be part of the problem as these are not foolproof and do not always work with all wiring harnesses. Therefore, I would check each of the pins with an actual circuit tester while the respective signals are active. These are much more accurate than the above testers. In regards to the T-One Vehicle Wiring Harness part # 118760 which is a fit for your 2018 Honda Pilot, there are...
    view full answer...
  • Can Curt LED 4-Way Flat Connector # I26 be Left on Vehicle Indefinetely
    Leaving the Curt LED 4-Way Flat Connector # I26 plugged into a 4-way for an extended period of time would not be an issue at all. Since you used dielectric grease like the part # 11755 you wouldn't have to worry about corrosion either.
    view full answer...
  • Availability of Curt 4-Way Circuit Tester I26
    We do have the tester you are looking for with the # I26. I think the confusion is that the part number is not 126 as its I26.
    view full answer...
  • Vehicle Side 4-Way Trailer Connector Plug-in Circuit Tester Lights Light Up when Connected
    If the lights on a 4-Way trailer connector tester such as # I26 light up when connected that means that those circuits are receiving power. It doesn't take much power to light up these small LED lights so even residual current could set them off. This is typically more likely on aftermarket installed trailer wiring harnesses that have a connection to the battery to power the trailer lights. It could also indicate a short circuit if the lights stay on all the time. The likely cause is a...
    view full answer...
  • Malfunction Turn Signal Light on Sunline Travel Trailer
    The first step would be to check the wiring from the malfunctioning light all the way up to the connector. Make sure all the connections are reasonably clean and secure, and check for frayed wires. If everything looks good from there, I would begin to look at the tow vehicle wiring. Check to make sure your connections are clean and secure. We have a few handy devices that could help you check all this. You could use a circuit tester like part # 40376 to check to see what connections are...
    view full answer...
  • Testing the Hopkins 4-Way Connector Not Showing Power on a 2009 Chevrolet Equinox
    You can test the Hopkins # HM11141265 by using a circuit tester like part # I26 while you have a helper activate the various light functions on your 2009 Chevrolet Equinox to make sure that the correct signals are coming through. If they aren't then you have some bad wiring on your Equinox (granted you installed the fuses and relays and they are okay). If you do get signals then you have a wiring issue on your trailer. This can be traced back to a faulty ground or damaged wiring. Make...
    view full answer...
  • Can I Get A Standalone Curt Wiring Converter For My 2017 Toyota Highlander
    I did some research and I checked the Curt website to see if you can get the converter for your 2017 Toyota Highlander separately. You will have to get the Curt T-Connector Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # C56217, to get this converter. I have included a product description link and a video of this part being installed on a 2017 Toyota Highlander below.
    view full answer...
  • Fuse Blows on 4-Way Harness When Using Circuit Tester 2013 Jeep Compass
    It sounds like the 4-way tester you are using like part # I26 has a short somewhere which is in turn causing the 10 amp fuse on the Curt T-Connector Vehicle Wiring Harness part # C56344 for your 2013 Jeep Compass to blow. What I recommend doing is testing each circuit with a standard test light like part # 40376 to check for function. If all is good then you know the problem was in the 4-way tester you are using. All of the converter boxes used in Curt's wiring harnesses are tested prior...
    view full answer...
  • Trailer Hitch and Wiring Recommendation for 2014 Toyota RAV4
    For a trailer hitch for your 2014 Toyota RAV4 we have the Draw Tite hitch part # 75235 that you referenced which is a confirmed fit and would work well. This would have been what I would have recommended you since it has the best capacities and price so you are on the right track. Then for trailer wiring the Tekonsha kit part # 118578 that you referenced is the best choice as it is the most reliable option we offer too so it's the way to go. To test this 4-way we have the # I26 that you...
    view full answer...
  • How to Wire LED Replacement Trailer Lights
    If you are looking at and LED Trailer Tail Light like part # STL8RB, then you will not need a converter to make it compatible with the 4-Way Wiring Harness on your truck. You will need to figure out the wiring on your trailer to make sure that you get all of the wiring done correctly. You can use a Circuit Tester # I26 for that purpose. All you have to do is hook up your new LED lights using the following information. Brown is for tail lights Green is for stop and turn White is for ground The...
    view full answer...
  • No Function on any Right Side Lights on Trailer Behind 2010 Subaru Forester
    I have found the best way to find a bug in an electrical system is by process of elimination. Eliminating possible sources will eventually lead to the right spot. First thing I would do, is check the 4-Way connector on your Subaru Forester. Using a circuit tester like part # 40376 or a 4-Way tester like part # F5CT or part # I26. The white wire is ground, the yellow wire is left turn and brake, the green wire is right turn and brake, and the brown wire is tail lights. Chances are, the...
    view full answer...
  • Comprehensive Vehicle Side Trailer Connector and Wiring Tester
    Most of the vehicle end trailer connectors we have will test for voltage on the circuits. If there was a short to ground then all of the lights would light up on the tester and you would know there is a problem. We do have a comprehensive trailer side tester, # 8010, which goes much further than any of the regular testers like # I26. But it is not designed for the vehicle side. For the vehicle side we have # HM50918 that can test multiple connector types on a vehicle (4-Flat, 6-Way round,...
    view full answer...
  • Is There a Way to Trick Parktronic Sensors on a 2016 Mercedes-Benz Sprinter for a Bike Rack
    I am not sure if this will have enough draw but we have testers like the Curt LED Tester # I26 which puts a small load on a 4-Way Flat connector. This is used to make sure that your wiring is working correctly but it may be enough to trick your sensors. If you have a 7-Way then I recommend using the Tow Ready # 20142 as it will simulate a draw as well. Please note that both of these products are designed to be plugged in for short periods of time and haven't been tested for prolonged...
    view full answer...
  • Is Dealer Activation Required for Trailer Wiring Harness # C55384 on 2015 Jeep Grand Cherokee
    When you install the Curt T-Connector Vehicle Wiring Harness for Factory Tow Package - 4-Pole Flat Trailer Connector # C55384, it may be necessary to see a local Jeep dealer to activate the tow package wiring circuit. Some vehicles have the active tow package wiring and others do not, so you will know as soon as it is installed if this is required or not. If you test the function using a tester like # I26, a circuit tester like # PTW2993, or connect it to a trailer, you will be able to...
    view full answer...
  • Recommendation on a Trailer Light Tester
    I found a solution for you. The Tow Ready 7-Way Trailer Vehicle Tester, # TR20117, will allow you to test the lighting functions on your vehicle's 7-way trailer connector. The plug connects and used LED lights that will display if you have a properly functioning 7-way or if there is an issue with the vehicles signal output at the connector. Also, if you are needing to test a 4-way flat connecter, I recommend the Curt LED 4-Way Tester, # I26.
    view full answer...
  • How to Determine if a 2017 Toyota Highlander has a Factory Tow Package
    To determine if a 2017 Toyota HIghlander has a factory towing harness, start by opening up the rear hatch. Then, lift up on the rear compartment panel and pull it out. Remove the two driver-side panels by pulling up on them. There, you may see a factory 4-pole. If you do, then you know for sure you have the factory towing harness. If you do not, you may still have one that didn't come with the 4-pole connector so continue to the next steps. Pull up on the tabs connecting the floor covering...
    view full answer...
  • Trailer Running Lights Not Working On 2019 Infiniti QX 60
    The first thing you will want to do in order to determine why your trailer's running lights are not working is to test the vehicle wiring first. The Curt LED 4-WayTester # I26 is a great tester that simply plugs into your vehicle's 4-Way plug and lights up according to which light functions are working properly. If you happen to have a 7-Way installed, then use the 7 Way Tester # TR20117. If this test verifies that the vehicle's wiring is working correctly, then you can be sure that...
    view full answer...
  • Troubleshooting A Turn Signal That Is Not Working On My Trailer
    This is something that can be remedied, but it will take some troubleshooting. This will be easier if your wiring harness is something like the T-One Vehicle Wiring Harness with 4-Pole Flat Trailer Connector, part # 118578. This is a plug and play system, so you will not have to check any spliced wires during the troubleshooting. If your setup is something like the 4-Pole Trailer End Connector, part # 18004, you attached to your question, you may have to do some wire splicing. I recommend...
    view full answer...


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Info for this part was:

Employee Joe V
Test Fit:
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Employee Andrew K
Video by:
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Employee Joshua S
Video by:
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Employee Jameson C
Expert Research:
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Video Edited:
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Employee Cole B
Installed by:
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Employee Ryan G
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Employee Wilson B
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