Fast trailer light options?

I've been trying to do this right and hitting a wall, does anyone know of a quick and dirty tie in that does not cut wires? Most boxes clip wires one way or another and I'd still like to do a proper install latter.
 

220629

Well-known member
You don't mention model year. If you aren't in a rush an OEM trailer light package MAY allow you to have the TSP safety package.

Quick install.

The wires don't need to be clipped. They can be tapped.

Some people strip back a bit of insulation and solder in the taps. Alternatively there are various style wire tap connectors which pierce the insulation.

The important thing is to seal all taps to exclude moisture and avoid corrosion.

On my 2004 I mounted an aftermarket powered trailer light module up in the rear tail lamp cavity. For the 2006 I realized that the aftermarket module is potted and completely waterproof. I mounted that one under the van near the spare tire and tapped all wires under the van body. It saved a bunch of screwing around.

The module and brake controller information for the T1N will work for your NCV3 model.

...

*******************************

20170809 Edit: Members often ask what parts to buy.


I mounted this to the under panel just aft of the spare tire.
Tekonsha 119147 ModuLite HD Protector Trailer Light Power Module
https://www.amazon.com/gp/product/B00ASY29C0/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1

I used ss hose clamps to strap this to the hitch structure.
Hopkins 47185 Multi-Tow Adapter
https://www.amazon.com/gp/product/B0002Q80GS/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1

Older model timed brake module. (Fine for small(er) trailers. Ignore "Does not fit".)
Reese Towpower (74642) Brakeman Timed Compact Brake Control
https://www.amazon.com/gp/product/B0016KA9PY/ref=oh_aui_detailpage_o05_s01?ie=UTF8&psc=1

Some (Eg. - Sailquik Roger) prefer a more modern proportional brake controller
https://www.amazon.com/s/ref=nb_sb_...rh=n:15684181,k:proportional+brake+controller

Fits a 2500 140 WB T1N
Reese 33089 Class III Custom-Fit Hitch with 2" Square Receiver opening, includes Hitch Plug Cover
https://www.amazon.com/gp/product/B000RNW5PI/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1
Trailer Wiring OEM Harness vs. Light Module
https://sprinter-source.com/forum/showthread.php?p=59089

:cheers: vic
 
Oops. It's a 2016.

I've found a good deal on the dodge branded wiring, mine is Mercedes, and I was having a hard time figuring if the controller under the seat changed, I saw a mention of one part number covering something like 2007 to 2014.

Are those the only 2 parts I need? Reading the install thread I got confused dang it! I realize there will be some dealer programming involved.
 

Düsseldorfer

New member
If you're looking at the Dodge-branded kit, there's no programming. There's also no controller, and it will require cutting wires -- or, as Vic says, soldering taps, which is what I did.
 
If you're looking at the Dodge-branded kit, there's no programming. There's also no controller, and it will require cutting wires -- or, as Vic says, soldering taps, which is what I did.
Hopefully it doesn't make the computer on my 2016 angry, I see the difference in some photos, others seem to be the Mercedes part.
 

Hulabaloo

New member
Curious to know what route you went. I’ve been researching solutions for my ‘14 and finally decided on a pseudo factory harness. Mercedes says they no longer offer the harness (though they did a few months ago) but Dodge still does (82211251AB) for about $160 (ebay). I’m not above the MOPAR solution of cutting/soldering/shrink tube sealing the splices, but wonder if anyone has experience with these: https://www.posi-products.com/posiplug.html I suppose the 14-16 gauge taps would work... I’ve read more than once that solder joints have no place on a car, boat, or anything else that moves around a lot. I’ve done plenty myself, but before I knew better.

Tekonsha also makes a pretty nice 7 blade kit (TK22115) but I like the idea of maybe-possibly-someday having Mercedes teach the computer to keep ASR active while towing, which I understand some have had luck with.
 

220629

Well-known member
... but wonder if anyone has experience with these: https://www.posi-products.com/posiplug.html I suppose the 14-16 gauge taps would work...
I've used those taps before. They do a good job. The taps definitely support the tapped wire better and cause less wire insulation damage than do the typical crush type. I would apply a bit of Vaseline or other anti-corrosion before clamping them in.

...
I’ve read more than once that solder joints have no place on a car, boat, or anything else that moves around a lot. I’ve done plenty myself, but before I knew better.
...
Soldering fine if the proper flux is used and IF the conductors are properly supported. The transition region between the solder and the conductor is subject to stress and cracking. That is particularly true if any of the wire strands are nicked.

... Tekonsha also makes a pretty nice 7 blade kit (TK22115) but I like the idea of maybe-possibly-someday having Mercedes teach the computer to keep ASR active while towing, which I understand some have had luck with.
Double check that a MB dealership can... will activate the trailer safety TSP if a Dodge harness is installed. If not, I would explore the plug and play E-trailer option mentioned previously.

:2cents: vic
 
I went this route from another seller, not a bad way to do things and it is mostly plug and play, it plugs into the tail lights, add a ground, and run a hot lead to the battery hot terminal under the drivers right foot, under the van. I'd prefer tidier, but at least I wasn't hacking wires looking for trouble down the road.

Someone mentioned the dodge and Mercedes wiring kits are not the same, I couldn't verify either way.








Curious to know what route you went. I’ve been researching solutions for my ‘14 and finally decided on a pseudo factory harness. Mercedes says they no longer offer the harness (though they did a few months ago) but Dodge still does (82211251AB) for about $160 (ebay). I’m not above the MOPAR solution of cutting/soldering/shrink tube sealing the splices, but wonder if anyone has experience with these: https://www.posi-products.com/posiplug.html I suppose the 14-16 gauge taps would work... I’ve read more than once that solder joints have no place on a car, boat, or anything else that moves around a lot. I’ve done plenty myself, but before I knew better.

Tekonsha also makes a pretty nice 7 blade kit (TK22115) but I like the idea of maybe-possibly-someday having Mercedes teach the computer to keep ASR active while towing, which I understand some have had luck with.
 

sailquik

Well-known member
Dodge NCV3 Sprinters were sold in 2007-2009.
Mercedes Benz Sprinters are 2010-2019.
Trailer Stability Assist (TSA) was not offered (nor even invented) until 2012.
So, if you have an NCV3 Sprinter, USA specification, 2012 or later, you need the
Mercedes Benz Trailer Towing Harness Part # A906 440 00 064.
Wiring Kit Only (all models)
A906 440 00 064 all models
Work instructions are available in WIS.
The retrofit kits do not support TSA (Trailer Stability Assist) !!
So, even on the latest (2014-2019 MY Sprinters) you do NOT get (and cannot get)
TSA unless you order it on the original build of the Van.
https://www.mbpartscenter.com/oem-parts/mercedes-benz-electrical-wiring-harness-9064400064
MB Parts center has this part number (the Retro Fit Trailer Wiring Harness) for $19116.
Roger
 
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Hulabaloo

New member
This is the first vehicle I’ve owned that I can’t source nearly all needed parts from RockAuto or the like...what an experience. During countless calls to my local MB parts desk I’ve been told either the harness is only available when sold as a package with the hitch, or not at all. I finally decided to buy the whole package and sell the factory hitch off myself, when they claimed that the kit was no longer available. I even resorted to contacting the dealer in CA who originally sold the van (and deals extensively in Sprinters) and they also told me that it was not available, though had to do more research and then never called me back. Two techs even emailed the MB mother ship to help me find answers. Never heard back on those either.

So with the part number that Sailquik gave me (thanks!) I called and he says its available...But he’s also not sure what exactly the part is for. The notes state that my van must have option E40, and when I ask to have my vin run, that is not listed on my build sheet. The notes say that without E40 I have to buy 3 or 4 other harnesses (0069,7204...) and numerous other small parts for it to work.

I wonder if his system is insisting that if my van is to be retrofitted with a trailer tow package, that it looks exactly like it would have come from the factory, ie with the accelerometers and all other wizardry to have a functional TSP etc. I explained that I just need a 7 blade connector in the back. He was willing to order the harness (even matched the website’s price sailquik linked to (thanks again!) because this has been dragging on so long. When he gets it in hand he’ll help me determine whether it’ll work or not.

After watching our new-to-us 4600 lb pop-up camping trailer sit in the driveway for a couple months I’d finally settled on the MOPAR harness from the older Sprinters that gets spliced into the lighting in back. It arrived yesterday and I was planning on installing it Monday when I’m back in town. I’d be happy to pay return shipping on it though assuming that the MB harness will work. If you have any insight on my theory above let me know.

Sounds like WIS is an electronic manual system that Mercedes uses? Can I get access to it? I have no intention of having Mercedes install this harness, so would love for it to come with instructions.
 

220629

Well-known member
Dodge NCV3 Sprinters were sold in 2007-2009.
Mercedes Benz Sprinters are 2010-2019.
Trailer Stability Assist (TSA) was not offered (nor even invented) until 2012.
So, if you have an NCV3 Sprinter, USA specification, 2012 or later, you need the
Mercedes Benz Trailer Towing Harness Part # A906 440 00 064.
Wiring Kit Only (all models)
A906 440 00 064 all models
Work instructions are available in WIS.
The retrofit kits do not support TSA (Trailer Stability Assist) !!
So, even on the latest (2014-2019 MY Sprinters) you do NOT get (and cannot get)
TSA unless you order it on the original build of the Van.

https://www.mbpartscenter.com/oem-parts/mercedes-benz-electrical-wiring-harness-9064400064
MB Parts center has this part number (the Retro Fit Trailer Wiring Harness) for $19116.
Roger
A couple small corrections.
TSA, or TSP as I recall the acronym, was invented and used on other MB models before it was available on the NAS aka NAFTA Sprinter. I believe the Trailer Stability was first available on NAS Sprinters in 2010.

Don't discount trailer stability from the mix if that is what is wanted. It may take some effort and $$$ to get.There was a post/thread that indicated an owner did have Trailer Stability added after the fact by a dealership. The process wasn't plug and play. Some details were revealed. I just did a quick search, but didn't find the post/thread for the details.

:2cents: vic
 

Hulabaloo

New member
Though nice to have, TSP (A?) isn’t really what is wanted. The van will continue to spend 98% of its miles shuttling the family around trailer-less, punctuated by the occasional road trip with the camper. I don’t think I could justify spending thousands to retrofit the feature. I’ll just have to use good old fashioned driving skill while pulling with the Sprinter, just like every vehicle I’ve pulled with before.
 

sailquik

Well-known member
Hulabaloo,
How will you integrate an electronic trailer brake controller into the MOPAR system you are going to add to the back of your
Sprinter?
If towing a 4,600 lb. trailer (any kind of trailer...travel trailer....car trailer......cargo trailer........boat trailer) you will need a
way to apply the electric trailer brakes.
With the MB system, you would get the green connector making it quite easy to install and integrate a very efficient trailer
brake controller system into your Sprinter.
With the Chrysler/MOPAR system you will also need to tap into the brake light switch, probably add an auto reset circuit
breaker to get power from the battery (located in the center of the cockpit under the floorboards).
The other components that Mercedes Benz suggests go under the driver's seat on the upper rail and include the required
sensors and control units to make towing your trailer truly safe,
Good luck!
Roger
 
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220629

Well-known member
Though nice to have, TSP (A?) isn’t really what is wanted. The van will continue to spend 98% of its miles shuttling the family around trailer-less, punctuated by the occasional road trip with the camper. I don’t think I could justify spending thousands to retrofit the feature. I’ll just have to use good old fashioned driving skill while pulling with the Sprinter, just like every vehicle I’ve pulled with before.
Given that as your expected use...
(I completely agree with your logic BTW.)

An aftermarket light controller will work as well as any factory harness. There are also plug and play harnesses for some NCV3 Sprinters to install an aftermarket trailer light controller. Tapping the brake light circuit for a brake controller trigger signal is no different than many other brand trucks.

Some general info is here including my suggestion for a traditionally wired light module in the first post.

Trailer Wiring OEM Harness vs. Light Module
https://sprinter-source.com/forum/showthread.php?p=59089

:cheers: vic
 

Hulabaloo

New member
I think standardizing our terminology would help a lot. I was, and possibly still am confused with the options out there. So there is what many are calling the OEM harness, which is the MOPAR solution, and the one I bought. This one has old school relays that, if installed as recommended, sit under the van in the elements and require splicing in 5 or six places near the taillights. (And yes, I’ll have to splice into the brake pedal signal wire, install a protected power lead to...) Then there is the aftermarket option (7 blade) from etrailer which does without splices and instead uses a cool harness that plug directly into the taillights and has a solid state solution (ModuLite?). (But will still require tapping into the brake pedal signal) What I didn’t realize is that my van, a 2014, may be able to get the TRUE OEM solution (for my model year), though I’m not sure this will actually work until I get eyes and hands on it. I ordered the Mercedes part that Sailquik linked to, and am hoping it will work.

I’m just now realizing though that there might still be a requirement to have the dealer teach my computer to play nice with the new harness. I thought that ($300?) requirement was only if I bought the rest of the sensors and harnesses to activate TSA, which I realize now isn’t really an option for me. So for a guy like me, who wants a “powered”, system rather than one that tries to tap significant amperage from splices in the vans lighting circuits, and a seven blade plug, I have three good options:
Mopar: $145 shipped
ETrailer: $177 shipped (currently on sale)
Mercedes: $192 shipped (because the dealer matched the online price)

The Mercedes solution would be my first choice, though I didn’t plan on needing to get the dealer involved in the re-flash.

I think I’ve got a good handle on the Mopar and etrailer/ModuLite solution, but let me know if anyone knows if this is how the Mercedes one works:
I buy part A906 440 00 064 for my 2014 144” non-E40 option equipped van, install it myself (I’ll see if I can talk the dealer into printing off instructions). I won’t have to cut or splice, and afterword will have a green plug under the seat that I can buy/build a mating plug to that will connect to the trailer brake controller of my choice. Since my trailer has two braked axles I should consider supplementing the blue trailer brake supply line with another conductor. (Just like with the Mopar or Etrailer solution).

If I can’t make my peace with the Mercedes solution I may still return the Mopar harness since I didn’t realize the relay / location situation when I bought it. (Though there is a post somewhere on here where someone found a way to tuck the relay package up into the van body, which I may look into first).

Sound about right? Sailquik, does it sound like the Mercedes harness alone, after factory re-flash, will get me what I need?
 

Hulabaloo

New member
Well my Mercedes harness came in yesterday, and it looks exactly what I was hoping for. I'm feeling optimistic enough that I scheduled a service appointment next week where I'll have them turn it on. (I also have an airbag recall that will get done). The service manager seemed open to emailing me installation instructions from WIS, but I've not heard back yet, and kind of doubt I will unless I hound them. What is the best way for a DIY-er like me get access to this info?

Also, There are 6 plug ends on the harness, plus a large ring terminal and 5 or 6 blade terminals and at least one loose wire end. I'm assuming that the large end plugs into the back of the trailer plug, and most of the smaller ones go under the seat, with others going unused due to my lack of TSA. I didn't realize that the harness wouldn't come without the trailer plug. I don't mind going aftermarket here, but am not sure if these plugs are pretty standard, or if I need a Mercedes specific one. I found this, a Dodge, Chrysler adapter: https://www.etrailer.com/Custom-Fit-Vehicle-Wiring/Pollak/PK11893-11933.html
That looks like it will work, though the snap may not be quite right.

So if Mercedes can't look up parts that are "greyed out" on their computer after entering my VIN, how are the experts here, like Sailquik, who found this harness part number getting them when the dealer can't? Cause it would be nice to see what Mercedes' own trailer plug looks like.

Thanks again guys.
 

Attachments

Cheyenne

UK 2004 T1N 313CDi
So if Mercedes can't look up parts that are "greyed out" on their computer after entering my VIN, how are the experts here, like Sailquik, who found this harness part number getting them when the dealer can't? Cause it would be nice to see what Mercedes' own trailer plug looks like.
He uses the VIN of a van which DID have the option from the factory so they are not then 'greyed out'.

Keith.
 

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