Since the Curt 56360 is no longer available, it appears that some owners have questions about installing the suggested Curt 56391. Here are some images and instructions on how to install the Curt 56391 (and Hopkins 47185) in a 2015 Golf Sportwagen TDI. Note that driver side and passenger side references are for North America.
The connector contact pins of the Curt 56391 wiring harness are arranged for plug-and-play with the 2017 Golf Alltrack and therefore the yellow (left turn) and green (right turn) wires of the harness are not in the necessary locations for the 2015 GSW. Relocating several of the contacts in the wiring harness is therefore necessary.
Image 01: Curt 56391 (labeled for 2017 VW Golf Alltrack) and a generic Hopkins 47185
The wiring of the Golf Sportwagen is multiplexed and the lights receive their commands via Pulse Width Modulation (PWM). It is my understanding that the signals are +0.5v for the tail position lights, +5.0v for the turn signal lights, +12.0v for the brake lights and that the relevant wires in the vehicle can be identified via back-probing using a fast response multi-meter. The wires can also be identified via the wiring diagram for the 2015 Golf Sportwagen. Specifically, the left turn signal in the vehicle is the 0.5mm schwarz/weiss (black with white tracer) wire as shown below.
Image 02: Image of left side wiring diagram for 2015 Golf Sportwagen
So, for the Curt 56391 harness connectors on the driver side, the yellow wire of the harness needs to be relocated (i.e. swapped with the relevant white wire) in order to match with the 2015 GSW vehicle wire that is black with a white tracer. Note that out of the box, the yellow wire is positioned in line with the black/red vehicle wire. The brown wire of the Curt harness conveniently remains in place – in line with the 2015 GSW vehicle wire that is gray with a black tracer (as shown below prior to swapping).
Image 03: Image of left side connector (before modification)
For the Curt 56391 harness connectors on the passenger side, the green wire of the harness needs to be relocated (again, swapped with the relevant white wire) in order to match with the 2015 GSW vehicle wire that is black with a green tracer. Note that out of the box, the green wire is located in line with the black/purple vehicle wire (as shown below prior to swapping).
Image 04: Image of right side connector (before modification)
Connector contact pin removal is easily accomplished via a proper VAG connector removal tool – some owners report successful improvising via grinding the tips of tweezers or reshaping small cotter pins. A pair of tools is available from
IDParts (on back-order at the time of this writing) or a 3-piece tool kit (Schwaben 025682SCH01A) is available from
ECS Tuning.
Image 05: Image of Schwaben 025682SCH01A tool kit
The removal tool is quite small – the grip size being about half that of a typical workshop screwdriver handle – but it works very well.
Image 06: Image of Schwaben tools
The tangs of the pin removal tool are inserted into small rectangular holes that straddle the contact that is to be removed. As the tangs are inserted, they push against two metal barbs on the sides of the contact, flexing the barbs inwards, thus allowing the contact and wire to be pulled out of the connector housing without the barbs catching (see photos by Nuje posted earlier in this thread). Note that the housings also have plastic latches on their exterior shells that need to be carefully pried upwards and unsnapped to allow the contacts and wires to be fully removed from the connector housing. Also note that the contacts do have a certain orientation and thus need to be re-inserted in their new locations correctly (in other words, don’t unintentionally clock the contacts by 90 degrees during re-insertion).
Image 07: Image of pin removal tool use
The trailer module can be mounted in several locations. My preference was to mount it to a flat region of sheet metal near the forward corner of the Styrofoam tool case. In addition to the adhesive-backed double-sided foam provided I also opted to mechanically fasten the module’s mounting tab to an existing hole in the vehicle’s interior sheet metal. The white ground wire of the module is anchored to a vehicle grounding post slightly forward of the module location (not visible in photos). Access to the threaded grounding post required partial removal of the trunk side panel. Positive power to the module is from the 12v accessory outlet on the opposite side of the trunk, as discussed elsewhere in this thread (in other words, I did not run a dedicated positive wire underneath the full length of the vehicle all the way from the battery). Tapping into the 12v accessory outlet is perfectly adequate since the vehicle will be used to tow trailers that are fitted with LED bulbs.
Image 08: Side access panel removed
Image 09: Detail of Curt trailer module installation
Image 10: Image of the installed left side (modified) connectors
Image 11: Image of the installed right side (modified) connectors
Instead of having the trailer ribbon cable and 4-pin connector lay loose in the trunk area, I preferred instead to have an exterior receptacle for both 4-pin SAE and 7-blade RV type plugs (note that for the 7-blade, only 4 of the contacts are being used). The bracket of a Hopkins 47185 was riveted to the lower surface of a
Westfalia 317 132 600 001 towbar – to the left side of the hitch receiver. Enough spacing was provided to allow a 7-blade RV plug to be inserted without interference from the 50mm hitch. The Westfalia hitch is available from
PF Jones in the UK.
Image 12: Hopkins 47185 mounted to the left of the hitch receiver
Image 13: View from below Hopkins 47185 showing routing of 4-conductor ribbon cable
Unlike the regular Golf, the Golf Sportwagen already has a cutout in the rear valance panel. However, the stock cutout extends very little on the driver side and quite far on the passenger side (in other words, the VW factory cutout is not centered with respect to the middle of the hitch). Since the Hopkins 47185 was fitted to the driver side, the size of the cutout on the left side was increased (to the same extent as the right side) in order to provide necessary room for the Hopkins receptacle.
Image 14: View from below bumper showing extended cutout in the rear valance panel
