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smurph
08-22-2018, 04:51 AM
I've searched existing threads but didn't find any issues similar to mine.

I have a 2013 2500 cargo. It has the E40 trailer wiring harness. I just installed a hitch and now trying to connect the Round harness in the receiver bracket. I attached a quick connect (factory to round trailer socket) but not getting all signals.

I get power
I get lights
No left hand signal
Right hand signal works but flashes short - not quick but the signal doesn't last long each pulse.

Wondering where I go from here. I've taken a tester to all the circuit breakers on the left side of the drivers seat as well as the fuses by the hood release.

Is there anywhere else I should be looking? Is there a relay causing any issues? I'd much rather retain the factory set up than abandon it and install an aftermarket wiring harness.

Thoughts? Should I pull the drivers seat and check any fuses there? Just concerned as I'm getting some power to the end of the harness but not all.

ptheland
08-22-2018, 05:09 AM
The factory harness does not give reliable signals without a trailer connected. (Or at least actual incandescent bulbs.) It’s also known to be flakey with led lighting.

So how are you checking the harness?

smurph
08-22-2018, 05:14 AM
Howdy Peter,

I was just using a standard 12v tester (with bulb) on each wire of the harness as they were engaged from the cab. Lights.... brake.... signal....

I've heard they can be flakey. The harness was never used and was quite corroded as I just purchased the van from a friend of mine. It would have been nice if there was a protective cap installed if it wasn't going to be used. Our winters are hard on this type of thing.

autostaretx
08-22-2018, 04:59 PM
The NCV3 tests for the existence of a trailer by pulsing the (if i recall correctly) parking lights circuit... if you have LEDs there, you'll see them blink, even with the Sprinter off.
(it could be the brake lights ... given the usual dual-'filament' bulbs, people are poor at distinguishing which half is blinking)

If it does not "see" a trailer, not all of the trailer pins get powered when their various actions are called for.
(if it does see a trailer, it disables ParkTronix)

(i vaguely recall that one circuit does always get driven, trailer or not ... but i can't recall which circuit (there are threads about this...))

Does your "with bulb" tester (a) use an incandescent (b) have dual filaments for the brake/tail situation?
The Sprinter would be happier with multiple incandescent bulbs, not just one.

--dick

ptheland
08-22-2018, 05:34 PM
Howdy Peter,

I was just using a standard 12v tester (with bulb) on each wire of the harness as they were engaged from the cab. Lights.... brake.... signal....

That may not be an adequate test tool for a Sprinter. The factory trailer harness doesn't work like your old truck's wiring. The Sprinter factory harness (and some aftermarket ones) includes a computerized module that communicates with the rest of the vehicle's electronics. If it doesn't think a trailer is connected, it shuts off. It doesn't get it's signals from the wiring to the tail lights, it gets computerized signals from the van's other computers. Those tell it when to turn on and off the various lights.

The best way to test it is to hook up a trailer. Until you've done that, I wouldn't definitively say there is a problem.

I've heard they can be flakey. The harness was never used and was quite corroded as I just purchased the van from a friend of mine. It would have been nice if there was a protective cap installed if it wasn't going to be used. Our winters are hard on this type of thing.

They're only flakey when trying to test with 20th century tools. Testing with 21st century tools - basically a diagnostic computer - is the only way to really test, short of hooking up a trailer.

As to harsh winters, the only place I can think of that is exposed to the elements is the actual electric connection at the back of the van. The wiring and insulation should be just fine in the cold and salty wet stuff. The other end of the wires is under the driver's seat (port side seat) and protected from the elements. (At least until the sheet metal rusts through! :lol:) A bit of cleaning of the rear connector should be the only maintenance needed.

smurph
08-23-2018, 03:12 AM
The NCV3 tests for the existence of a trailer by pulsing the (if i recall correctly) parking lights circuit... if you have LEDs there, you'll see them blink, even with the Sprinter off.
(it could be the brake lights ... given the usual dual-'filament' bulbs, people are poor at distinguishing which half is blinking)

If it does not "see" a trailer, not all of the trailer pins get powered when their various actions are called for.
(if it does see a trailer, it disables ParkTronix)

(i vaguely recall that one circuit does always get driven, trailer or not ... but i can't recall which circuit (there are threads about this...))

Does your "with bulb" tester (a) use an incandescent (b) have dual filaments for the brake/tail situation?
The Sprinter would be happier with multiple incandescent bulbs, not just one.

--dick

I will have to drive to a buddy's place and hook up his trailer and see what happens.

My tester is a single incandescent bulb style. It's been through 8 motorcycle builds and 4 off road Toyota builds. Guess I need a German equivalent for the Sprinter :D

smurph
08-23-2018, 03:27 AM
That may not be an adequate test tool for a Sprinter. The factory trailer harness doesn't work like your old truck's wiring. The Sprinter factory harness (and some aftermarket ones) includes a computerized module that communicates with the rest of the vehicle's electronics. If it doesn't think a trailer is connected, it shuts off. It doesn't get it's signals from the wiring to the tail lights, it gets computerized signals from the van's other computers. Those tell it when to turn on and off the various lights.

The best way to test it is to hook up a trailer. Until you've done that, I wouldn't definitively say there is a problem.



They're only flakey when trying to test with 20th century tools. Testing with 21st century tools - basically a diagnostic computer - is the only way to really test, short of hooking up a trailer.

As to harsh winters, the only place I can think of that is exposed to the elements is the actual electric connection at the back of the van. The wiring and insulation should be just fine in the cold and salty wet stuff. The other end of the wires is under the driver's seat (port side seat) and protected from the elements. (At least until the sheet metal rusts through! :lol:) A bit of cleaning of the rear connector should be the only maintenance needed.

Yup. I'll drive over to a friends house and hook up his trailer and see what happens. My tester was made in 2002 so I guess i'm still using 21'st century tools :smirk:

I'm sure the harness wiring itself is fine - though I've seen abrasion issues in the past with motorcycles eating right through the sheathing and causing grounding issues. As for the exterior end - that's what I was referring to. When I pulled it down from the underside of the chassis, it was corroded to all hell. I tried to clean it up but to no avail.

sailquik
08-23-2018, 04:11 AM
Murph,
The factory wiring harness has a plug that goes in the back of the receptacle that was supposed to be tie wrapped
to the factory ORIS tow crossmember/receiver.
Did you Sprinter NOT come with the factory cross member?
Have you looked under the driver's seat for the green trailer brake connector?
If the plug behind the round receptacle at the rear of the Sprinter looks OK, you can easily get another
receptacle and plug it in, there by getting all new contacts and the alignment of all the spade contacts in
the receptacle.
Check the part number and manufacturer on the receptacle you have, and simply buy another one, then
remove the old one and replace it with the new one.
There may be some fuses on the LH side of the seat box, but why not get the "fuse map" that's in the
clear plastic documents pouch normally found in the glove box?
Roger

smurph
08-23-2018, 04:19 AM
Hey Sailquik ....

that's the funny thing. My build sheet says it has the factory wiring E40 and yes, it has the green plug under the seat. However there isn't a factory ORIS receiver installed on the vehicle.

I just recently installed a receiver which lead to my questions. There was never a round receptacle - only the rectangular one at the rear of the vehicle which was all corroded. A friend of mine works in a trailer/shock/spring shop and supplied me with an adapter which is plug-and-play from the rectangular female receptacle at the back of the van and makes it into the Round 6/7 pin plug for use with most trailers out there. He suggested bypassing all the existing wiring and running a new relay etc etc. I would prefer not to do that and to find out why it's not working.

I've gone through every fuse beside the front drivers seat as well as beside the hood release and all are working fine.

sailquik
08-23-2018, 12:21 PM
smirph,
I expect you can purchase a replacement for the corroded connector and pins from a MB Sprinter dealer, then trim and re-pin the wires into the rectangular connector and add the angle bracket and round female receptacle.
Have you tried one of the multi pin trailer plug test connectors?
Perhaps hooking it to a trailer is the easiest first step.
Since it's a 2012 you should have the TSA module as well as the trailer brake module under the drivers
seat on the upper bar if I recall correctly from the 2012 I had.
Yes, very strange that your Sprinter had the E40 Option but no cross member.
Wonder if it was at a dealer and they simply took the cross member/receiver off and put it on
some other Sprinter.
Roger

96r50
08-23-2018, 03:40 PM
FWIW, my 2016 also has the E40 trailer wiring (7 pin connector at rear, green brake control connector in driverís seat base) but did not come with a hitch.

autostaretx
08-23-2018, 03:59 PM
Yes, the "wiring for a trailer" and "trailer hitch installed" are two different options.

Here's the 2007 diagram of the trailer hookup (rectangular connector on lower right)

https://sprinter-source.com/forum/attachment.php?attachmentid=96503&d=1524764171

That drawing is an extract from a 3rd party suss-out of the Sprinter's wiring: http://diysprinter.co.uk/reference/07_Wiring-sprinter-2500.pdf

The original can be enlarged with much more clarity.

--dick

Aqua Puttana
08-23-2018, 04:53 PM
... - only the rectangular one at the rear of the vehicle which was all corroded.
...
The little bit of DC voltage which is most always present on the connector pins will accelerate corrosion in road salt areas. I have learned to keep a coating of Vaseline and a cap on my connectors. There are also purpose specific protectants.

... He suggested bypassing all the existing wiring and running a new relay etc etc. I would prefer not to do that and to find out why it's not working.

...
I would only use an aftermarket powered trailer module as a last resort. Your 2013 with factory trailer wiring now includes TSP trailer stability capability. An aftermarket module will not include that safety feature.

The above said, the TSP feature is less important when towing a small(er) trailer, and especially any trailer without electrically operated brakes. The TSP activates/needs the electrically operated brakes for full operation.

:2cents: vic

smurph
08-24-2018, 12:31 AM
Hi Aqua,

I wish the previous owner had taken more care in protecting the plug. Oh well.

TSP is the main reason I don't want to just rig it up and bypass the original wiring.

First i'll try and connect to a trailer. Doubt it will work. Then i'll order a replacement plug and wire it in, connect to the adapter and see if magic happens.

Thanks to everyone's help here. Fingers crossed.

smurph
08-24-2018, 12:35 AM
https://sprinter-source.com/forum/attachment.php?attachmentid=96503&d=1524764171
--dick

Hey Dick - I don't see any space in the engine compartment for the relays. The left (drivers) side of the rear area of engine - where some have installed a second battery - doesn't have any relays that I can see. I have the computer (i believe that's what it is) with the fins etc but nothing else.

Thoughts?

Aqua Puttana
08-24-2018, 12:53 AM
Hey Dick - I don't see any space in the engine compartment for the relays. The left (drivers) side of the rear area of engine - where some have installed a second battery - doesn't have any relays that I can see. I have the computer (i believe that's what it is) with the fins etc but nothing else.

Thoughts?
My recollection is that there is a group of relays located in the rear pillar. Passenger side if memory is correct. Nope... driver side in the USA.

...
Has relays and wiring in body cavity that get wet and fail.

My recollection is that the T1N OEM suffers the wet relay problem. I didn't dig up any posts. Here's some NCV3 comments related to wet relays and failure.
Brian, we were informed by our neighbor last night that one of our tail lights was on. I went to check it out and sure enough the left light was on, so I disconnected the batter, TA DAAA the light and everything else went dark. Connected the battery again and the light came back on, disconnected the battery again and went inside. Today I checked this great site and found your message. Went to our 2007 NCV3, found the 3" plug and pulled the DRIPPING wire harness out. I then found the drain hole and got out of the way of the steady stream of water. I connected the battery again and found one of the relays was warm, not hot AND the light did not come on unless directed by the light switch. Thank you so much for your message!

Funny thing is, same thing happened to me. First, I noticed that you have an aftermarket towing hitch and harness. Is that correct? If so, try to disconnect your towing wiring harness from your main battery.
Dodge towing wiring harnesses consist of six relays. They are located below the tail light on the driver's side. When I opened mine, three of the relays were corroded and wet, but I only had to replace one. Check yours for any corrosion and if neccessary, change the relay. I got mine from the Dodge parts department at the dealership. To prevent it from happening again, make sure you move the relays up and isolate them so they don't get wet.
Hope this helped!
****************************
...

vic

smurph
08-24-2018, 12:54 AM
Thanks Vic!

sailquik
08-24-2018, 01:40 AM
Guys,
I think you are mixing T1N (Dodge or Freightliner) 2002-2006 and early NCV3 (Dodge/Freightliner 2007-2009) with >2010 Mercedes Benz/Freightliner NCV3 trailer tow harness's.
There are no relays anywhere near the back of a 2012 NCV3.
All the relays and towing modules (TSA/Trailer Brake Controller) are under the driver's seat.
They are most often located on an upper module mounting bar above the normal electronics
found in Sprinters without the towing harness.
Roger

autostaretx
08-24-2018, 01:45 AM
Hey Dick - I don't see any space in the engine compartment for the relays. The left (drivers) side of the rear area of engine - where some have installed a second battery - doesn't have any relays that I can see. I have the computer (i believe that's what it is) with the fins etc but nothing else.

Thoughts?
I wouldn't sweat that relay coil ... it's not part of the Trailer hookup, it's part of the normal Brake system (if you look at Figure 7 (Brake Controller) in the full 2007 wiring diagram, you'll see it there, too).

I see in an earlier "options" book that E59 was "wiring for trailer, but no control module"

Um... where do you have "the computer with fins"?

--dick

smurph
08-24-2018, 01:45 AM
Mine is a 2013 but would be the same as a 2012. Good to know they're under the seat.

Cheers

smurph
08-24-2018, 01:47 AM
Um... where do you have "the computer with fins"?

--dick

I know... i sound like a moron. I assure you i'm fairly savvy with most cars, motorcycles and such. I was told 'that's the computer' when I asked the foreman (friend) at recent shop.
Facing the vehicle. Open the hood. Lower rear right hand side. I'll snap a pic.

smurph
08-29-2018, 11:44 PM
Thanks to everyone for the help. I connected a trailer to the van and got both signals working nice and bright. But no power to the brake. I cut off the factory harness and installed a new 7pin adapter with leads. All is working 100% now.

Cheers