Videos are provided as a guide only. Refer to manufacturer
installation instructions and specs for complete information.
Rating: 
35 reviews
Code: 56146KIT
Retail:$72.00
Price:$47.18
Shipping Weight: 2 pounds
Shipping Special
Features:
Specs:
Warning: Overloading circuit can cause fires. Do not exceed lower of towing manufacturer rating
Read Mercedes-Benz E-Class's owners manual and instruction sheet for additional information.
Kit Includes:
Surface Mount Technology (SMT) is a method for constructing electrical circuits where components are mounted onto the surface of printed circuit boards.
56146KIT Circuit Protected Tail light Converter with 4-Flat End, Circuit Tester and Quick splices
Video of Curt Upgraded Circuit Protected Tail Light w Converter Hardwire Kit - 4 Pole End (Includes Tester)
Videos are provided as a guide only. Refer to manufacturer
installation instructions and specs for complete information.
Today on our 2003 Mercedes M Class, specifically the ML 350, were going to install the Curt Circuit Protected 4-Pole Wiring Kit, part number 56146KIT. To begin our install, well first remove the tail light assembly here on the drivers side. There are two fasteners that well need to remove. Then well go ahead and pop the tail light assembly out of its position and use our circuit tester to identify which wires that well be tapping into to connect our converter box for our 4-pole. The blue wire next to the green wire is going to connect to our brown wire from our converter box. This will be our running light circuit.
The green wire will connect to the yellow wire to our converter box, which will be our left turn signal and the manufacturers orange wire will connect to the red wire to our converter box for our brake signal. Lets go ahead and use a quick connector provided with our install kit and make those connections now. With that done, well go ahead and take some black electrical tape and re-tape up the wires that we stripped back and cover our connection points. Now, well go ahead and take the white wire with a pre-formed ring terminal attached and secure it to the body of the vehicle. This will be the ground wire to our converter box.
Using the self-tapping screw provided, well go ahead and make that connection now. Now, well go ahead and use the two-way adhesive to secure our converter box here to a flat clean surface. Peel back the one side and secure it to the converter box and then the other side and secure it here behind the tail light assembly. Now, we can take the 4-pole wire and our green wire which will be the wire that will carry our turn signal from the passengers side to our converter box down between the bumper fascia and the sheet metal of the vehicle. Next, we can go ahead and take the black wire provided with our install kit and connect it with the black wire from our converter box.
Well feed it up from underneath and using the yellow butt connector provided to secure the two together. Then I'm going to go ahead and take some black electrical tape and wrap up this connection. Now, with all our connections made here behind the drivers side tail light assembly, we can go ahead and reinstall it. Next, Ill go ahead and remove the passengers side tail light assembly so that when we route the green wire, we can feed it up behind it. Now, we can get underneath the vehicle and start routing our wires.
Well take the green wire and route it over to the passengers side and our 4-pole will get routed to the hitch. Keep in mind when youre routing the wires, you need to be especially careful of excessive heat such as the exhaust or moving components such as the steering or suspension. In some cases, the green wire will not be long enough and youll need to add an extra piece to get all the way to the tail light assembly. As in this case, well go ahead and add a piece of green wire. Well strip back both sizes of wire using a blue butt connector, make this connection, and then well wrap it with electrical tape to keep out any dirt, dust, debris, or moisture. Next, we can go ahead and take some black zip ties and secure our wiring. Now, were behind the passengers side tail light assembly. We need to make a connection with the manufacturers turn signal. Well go ahead and strip back enough from the manufacturers tape to make our connection. Our green wire will be connected to the manufacturers pink wire to pick up our passengers side turn signal. Well repeat the same process that we did on the drivers side. Alright, now with the passengers sides tail light assembly connected, taped up and reinstalled, we can go ahead and get back underneath the vehicle and take our black power wire and route it to the engine compartment. Now, weve got our power wire run into the engine compartment, well go ahead and use some zip ties and secure it, and then route it over to the battery. Again, as I route my wire over the battery, well just use some black zip ties to secure our wire. Now that were at the battery, well go ahead and cut off any excess from our power wire. Next, we can go ahead and prepare to add our fuse holder. Well cut the fuse holder in half and strip back both ends. Well strip back our power wire then well add our yellow butt connector to connect the fuse holder to the black power wire and our ring terminal to the other end. Now, we can go ahead and take some black electrical tape and wrap up the butt connection. Now, were ready to go ahead and add the fuse holder terminal to the battery. Here will be a perfect location so well go ahead and add a nut to the positive battery terminal and secure our ring terminal to the battery. Now, we can go ahead and add our fuse to the fuse holder and install the cap. This will complete the install of our Curt 4-Pole Wiring Harness, part number 56416KIT, on our 2003 Mercedes M Class.
1998 E-Class by Mercedes-Benz Owners Who Purchased This Custom Fit Vehicle Wiring,Wiring Also Bought...
Average Customer Rating: 4.7 out of 5 stars (35 Customer Reviews)
by: Martijn S.05/10/2013
Is this review helpful?
Overall it looks like this harness will work. A couple of points that are good to know. Splicing into the existing drivers side wires is extremely tedious work standing in a very awkward position just outside the tail gate. The scotch splicers just barely fit clustered together since there is no slack in the car wiring itself. There is very little guidance given on how to run the power line to the battery. A make/model specific schematic showing suggested attachment points would really help. The power tester that comes with the kit doesn't work by attaching to the little posts as shown in the video. Perhaps I'm doing something wrong, but compared to the video this project seems much more difficult and time consuming. Allow for plenty of time and don't rush this project. If you can get the car on jacks it will make running the power wire much easier. Definite room for improvement, but the product does work if installed correctly. 79777
by: Russ05/10/2013
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Everything was included that was needed. Instructions were great for someone like myself who has limited knowledge of this kind of installation.79698
by: Tim F04/26/2013
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Everything relied reliably and installed perfect! The diagrams they included were really helpful and I was able to complete the install by myself which is saying a lot for a guy who is no good at all at electricity. I definitely recommend and plan on doing business with this company again.77938
by: Joe W.04/26/2013
Is this review helpful?
I ordered the 56146KIT for installation on my 2012 VW Jetta TDI. The package came with everything I needed and installation was very simple. etrailer was prompt with shipping and provided additional resources should I have trouble (I didn't). I am extremely satisfied.77900
by: Lawrence Stearns04/23/2013
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Working just great, thank-you! 77399
by: Robert04/21/2013
Is this review helpful?
I purchased the Curt wiring harness and it came with all the necessary parts and accessories. The instructions were generic making finding the specific wires a little difficult, but not a problem once I took the rear light out so I could find the brake light wire. Depending on the ability of the installer this could result in trouble. Details identifying the specific wires would have been nice. 77064
by: Conrad04/15/2013
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Easy installation, and so far has lasted longer than the "Valley" brand that I had previously used.76223
by: Jesse04/15/2013
Is this review helpful?
I installed this product in a 2013 Prius Plug-In. The install itself was fairly cumbersome, as there was a fair amount of disassembly required to access the necessary wiring. In the end, the product fit nicely and functioned perfectly. My only "complaint" was that the LED tester was so dim that it was very difficult to dicern on/off in the sunlight. 75995
by: Alan03/30/2013
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My wiring in my 1998 mazda( ranger) b4000 could not handle all the new lights from my new tent camper so I went on line to find a converter that was powered straight from the battery and found kit 56146 which works perfectly now. All my lights work and installation was a snap, I encased the battery wire in flexible tubing for extra safety. Every thing else I needed was in the kit, thanks to a quick deliver I got to go camping on time for Grandsons spring break safely. This kit is fused at the battery and is very safe in case of shorts or overloads. Al 73418
by: soccerdad03/02/2013
Is this review helpful?
Easy installation on the 2004 X3 3.0i. Very high quality kit. I simply followed the excellent video for the X3 also on this site at http://www.etrailer.com/Custom-Fit-Vehicle-Wiring/BMW/X3/2004/56146KIT.html?vehicleid=20049943. It installed just as explained and the adapter works perfectly. Tip: Make sure you have a good wire crimp tool like the one used in the video. Don't use pliers or the ones on the cheap flat stripper tool. You can get a set for about $10 at Lowe's or Home Depot. It will make all the difference. I am very happy with etrailer, great products, reasonable prices and great service. You can't go wrong. 68482
by: Roger02/13/2013
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The trailer wiring kit for my Nissan Murano, with the circuit protected tail light unit worked flawlessly. The instructions were easy to follow and the installation went well. The only difficult part was the testing of the wires to determine tail light, brake light and right /left turn signals, which was very time consuming, cumbersome and required an additional person. I am very happy with the Curt trailer tail light wiring kit.66182
by: ROBERT02/11/2013
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great product, it has everything you need to wire a trailer set up. Double sided tape not the greatest but it could be that i didnt clean the surface good enough.65661
by: Joel11/27/2012
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Mounted this on a BMW X1 (2013). This kit is not vehicle specific. I had plenty of Power cable as the battery is rear mount, but hardly an inch to spare for any of the other wires. The instructions were pretty vauge and there is no vehicle specific information to help you find the correct wires, etc... It would be nice if etrailer provided custom instructions to specific vehicles as Crutchfiled does for stereo installations. However, I'm no newbie when it comes to wiring, so I managed to get a very functional and clean install of this kit.60040
by: Darel D.11/22/2012
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Other than free tester not working product was exactly as described. I did not buy product for tester and have my own so once wires were located install was easy. Did not set off any alerts in car. Would recomend.59922
by: Russell c11/13/2012
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Great quality gives you everything u ne ed59374
by: 2006 X3 Trailer Hitch Install - harness10/15/2012
Is this review helpful?
Watch a youtube video to learn proper harness routing. There is a grommet already in place for the factory kit.57250
by: Darren R.09/20/2012
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I am very satisfied with the prompt and professional service with etrailer.com...55235
by: Scott I08/27/2012
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I got the tail light converter on time and as advertised, next day shipping, Thanks! Product is working great!53251
by: bonnie08/16/2012
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fine 51876
by: Pat08/09/2012
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Great product! Does not throw a light out code for my BMW 135i! VERY EASY INSTALL. Comes with everything you would need. No soldering required! Would recommend this to anyone...51097
by: Jim M.08/06/2012
Is this review helpful?
This is a good electrical design. Mounting may vary however. The 2011 VW Jetta has panels which must be removed so the adapter can be mounted. These are held on by plastic snap screws which may break if removed. Fishing the battery wire to the front can be challenging if you don't have the car on a lift. I persevered and it works great. 50721
by: Rod E07/24/2012
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Wiring was easy to install once the panelling was removed, instructions were easy to follow and things worked well without any problems. Thank you etrailer49219
by: BMW x307/19/2012
Is this review helpful?
Thank you for the follow up and the great customer service from pre-order to post delivery. Got my tow harness a day a head of schedule and already have it installed thanks to e-trailers step by step install video for my X3 BMW. Was a huge help considering places like U-haul didn't stock the correct parts or have the ability to install on BMW.48478
by: Richard S07/03/2012
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Product arrived sooner than expected and was safely packed. Delivered to all expectations for quality and service. Would recommend to colleagues!46656
by: John K06/06/2012
Is this review helpful?
The hitch was well packed and arrived on schedule. When I called seeking information the rep provided the information quickly. Will recommend to all my friends who have vehicles to buy here. Thank you for the outstanding service.43083
by: Michael W.05/30/2012
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Very fast shipping and great customer s ervice!42089
by: M. Yilmaz05/23/2012
Is this review helpful?
I used this wiring package in a 1999 Mercedes e430. Though I was nervous about successful installation, everything that was needed had been included in the package. I am happy that the installation was successful. Thank you eTrailer.com; I now know where to go for all my trailer needs. 41438
by: Anthony05/22/2012
Is this review helpful?
This part gets the job done at a fair price, and with ease. The included voltage tester makes finding the proper wires a breeze, and the instructional video made the rest of the install a no-brainer. It was my first electrical project of any sort, nonetheless on a car, and I was done in less than a couple hours; including taking apart my trunk and putting it back together. Only thing I would change is using a longer wire to go from the module to the battery - the included wire doesn't have a lot to spare, and took a couple tries to make it all the way to the battery without having to add any wire. Not a real problem, but a little more length would have been a luxury. In the end, it works, and it's pretty easy to make it look professional enough that people could think the car came equipped with this from the factory. Good deal if you ask me. 41316
by: scott01/14/2012
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wiring kit was excellent, no error messages or codes thrown on my car. 2006 bmw x3 msport29711
by: Jacj Y.12/10/2011
Is this review helpful?
Excellent service easy instructions and quality material. Customer for life27961
by: Jack q.12/09/2011
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I eexpected a well built trailer hitch, but the one you sent me as beyond what I expected. I wil recomend this item everyone and you have a customer for life.27918
by: dg11/25/2011
Is this review helpful?
The Jetta Sportwagen (2010-2011 confirmed, may be other years) has modulating taillights. Other Curt adapters may work. Figuring out the signals with modulating lighting can be painful. This is what works for 2010-2011 Jetta Sportwagen: Driver's side: Gray / Black (pin 1): Tail Light Black / Red (pin 2): Brake Brown (pin 3): Ground Black / White (pin 4): Left Turn Black / Blue (pin 5): Reverse Passenger's side: Gray / Black (pin 1): Tail Light Black / Purple (pin 2): Brake Brown (pin 3): Ground Black / Green (pin 4): Right Turn Black / Blue (pin 5): Reverse 27373
by: Chris D.04/29/2013
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The kit includes everything you will need to install the modulator on a ML-350. It is a perfect fit and they do not short change you on any wiring length, ties or wire connectors. If it wasn't for the video from eTrailer I doubt I would have been able to install this product so quickly and correctly. 78289
by: ben s01/30/2012
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supper easy to instal worked first time around!!30578
by: Mike L.09/15/2011
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Ordered on a Friday and had it delivered and installed by Tuesday night. Now my V-Dub is an "SUV"!!!23984
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