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My Towbar Torment

67K views 158 replies 39 participants last post by  Andy Touareg  
#1 ·
This is my first post, so I thought I should make it a good one. I took delivery of a MY13 Touareg TDI in February of this year. Like many people on this forum, my preference was for a Hayman Reese towbar rather than the VW OEM.

I know the towbar job involved removing the bumper from the car and internal trim, so I was reluctant to hand the vehicle over to just anyone. A few people I know had problems with local installers. One in particular damaged paintwork on the bumper and didn’t refit it properly.

To cut a long story short, I thought I would bite the bullet and do the job myself.

What a job turned out to be. The towbar job on the Touareg turned out to be a marathon.

The first job was to remove the bumper bar. This was relatively straight forward, but I cringed when pulling off the wheel arch trims.

When I was ready, my wife helped me remove the bumper and we rested it on a blanket. I removed the existing cross bar and bolted the new towbar on.

Now the hard part. To fit the lighting “ECU” module required the removal of the trim from the back of the car. The instructions from Hayman Reese were difficult to make out, so I had to take the job slowly. Removing the C panel covers was the hardest job of all. As with all panel removal, a lot of force is required, but there is always the chance that something will break. I used special plastic panel removal tools and my fingers.

It took me quite a while, but I finally had the panels on the left side removed.

I found the wire for the left indicator and connected it to the Hayman Reese harness using and ezy-tap.

I removed the RHS trim and found the wires I was looking for. Because I was also fitting a brake controller and 12V “hot wire”, I had the added complication of adding a 6mm cable for the earth and running a 6mm 12v positive cable as well as a 6mm brake control cable. The extra thick wires, made wiring the plug a bit of a challenge. I probably should have gone for a 12 pin flat plug, rather than the 7.

I spent the afternoon making the cut out in the bumper for the towbar and refitting it, as well as refitting the interior trim on the LHS. I had particular trouble with a “scrivet” and I had to remove the panel a number of times to retrieve a tool or the scrivet itself that had been accidentally dropped.

I then set about fitting the brake controller, which was time consuming, but with the trim already removed, a relatively easy job.

I tested the function of all of the lights with a multi meter and all checked out well.

I was disappointed that after refitting the trim that C pillar trims don’t seem to fit as well. I will ask the dealer to replace the metal spring clips when I take the car in for a service.

I backed the Touareg down the drive and plugged the boat trailer in. A neighbour was over by this stage and he confirmed that everything was working.

I fitted the towbar ball and hooked the boat up and towed it out. The towbar was at the perfect height , with the car in “normal” suspension height.

The car looked great with the boat attached. Nice and level. I was also very happy to find that the tail gate opened and cleared the bow of the boat. (just!)

I took the car for a drive. It pulled the boat brilliantly, which I was excited about, but my excitement was soon tempered when the brake controller (Tekonsha P3) started playing up. The display voltage was all over the place.

I had a look at the patch cable that joins the car to the trailer.

All seemed OK, but when I plugged it back in, the controller worked properly.

This is when the fun really begins!

I took the boat out the following weekend for another test drive. Each time I connect the trailer, everything is OK for about 2 minutes but then a problem arises. When I put my foot on the brake, the brake lights start flickering. When I fitted the brake controller, I took the brake signal required by the controller from the brake wire that goes to the 7 pin socket. (i.e. it's from the module, not from the car). After towing the boat for 2 minutes or so, the electric brakes go on and off with the brake lamp signal.

At one stage I pulled over and I had the left indicator on. I noticed the left indicator too was flickering.

I have done a heap of things to get to the bottom of this problem. I had to remove the interior trim again and replaced all of the ezy taps with soldered connections. I have supplied 12V to the module directly from the fuse panel. The earth of the module goes to an earth stud in the vehicle.

The boat trailer has LED lamps. I have heard that LEDs can be a problem, so I ran a test with normal incandescent lamps. That made no difference and the problem still existed.

I thought the Hayman Reese 4834 module itself may be faulty and All Vehicle Accessories, Campbellfield were fantastic and offered me a change-over. I thought that had solved the problem, but sure enough after driving for a couple of minutes, the problem re-appeared.

To make things a bit easier to diagnose, I fitted a relay under the dash that comes on when the brake pedal is pressed. It takes its signal from the red brake wire coming out of the module. (The same signal used for the brake controller). I can hear a "click" every time I put my foot on the brake.

So with nothing connected to the car, I can drive for 1 minute or so and each time I put my foot on the brake I hear a click. After a 2 and a half minutes, instead of hearing a single click, I hear several, as the brake signal continually goes on and off. At this stage, I remove the module in case I am risking damage to the car's electrics, or the module itself.

Given that everything is fine for the first couple of minutes, I was thinking that it may be something to do with the car's software

To understand a bit more about exactly what was going on I connected the Touareg to the boat trailer without the engine running. All lamps work as you would expect.

If I start the engine of the car, and put a brick on the brake pedal and leave the hazard lights on, the brake lamps and both indicators will start flickering after 2 and a half minutes.

I measured the voltage from the brake/tail lamp wire from the car. The one that goes into the module. It too started to fluctuate.

For whatever reason, the car decides to send some sort of signal through the wiring after it has been running for 2 minutes. It would appear that the Hayman Reese module can't cope with this signal.

It’s interesting to note, that if I didn’t have a brake controller with a display, I would not know this problem existed, because everything works fine when you first connect the trailer and check that everything works.

At this stage I concluded that the problem couldn’t be related to anything I had done and I contacted Hayman Reese technical support.

Hayman Reese were very good and were keen to look at the vehicle in case the 2013 model was in some way different to the '11 and '12. I had a technical guy visit today and he changed the module from the 4834 to the 4838. The problem seems to be fixed! (I still need to try out the brake controller though)
I would recommend that if you own a 2013 Touareg with Hayman Reese module that you connect your trailer, start the engine, put a brick on the brake pedal and turn the hazard lamps on. You may find that the trailer lamps flicker after 3 minutes or so. If this is the case, it would appear that a different module is required.
So if I had my time again, I would never have attempted the job myself. Too stressful!!
 
#141 ·
Thanks 'The Fizz' for your issues and glad to hear rectified. I'm awaiting a call back from Hunter VW on pricing and availability of towbar etc so this post of yours was very timely. Thanks also MM for your comments - btw is your avatar a burmese? Just asking as my wife is a wee bit crazy cat over the burmese - as we have two (and if she sees one on line and i say i'm responding to someone with one then all is good and she won't complain I am hogging the bandwidth etc). :D
 
#142 ·
@s12raider - avatar is a Devon Rex.

The craziest cat I have ever had. It kept growing into a giant of its breed - a super scale Devon Rex. Spielberg modeled the "gremlins" on his Devon Rex kittens...

My local vet kept taking photos and measurements every visit. I am sure he is written up in some vets' version of Ripley's Believe It or Not!
 
#144 ·
Hi Bill,
Yes it does look a bit of a dogs's breakfast as is :)
I think that if it were me I would just remove the original round 13pin plug & socket and shove them up under the bumper, secured with tyraps as they did with mine when the 12pin plug/socket was fitted....
 
#145 ·
Hi Bill,
Love the HR hitch I wish I had that fitted. I had the OEM hitch and electrics fitted by the dealer with 13 pin plug tucked up way above the bumper with a 7 pin plug coming out of that.
I recently had a Redarc Brake controller and Breaksafe monitor fitted (required in NSW only if towing more than 2,000Kg).
While the sparky was at it I got him to ditch the 13 pin and 7 pin combo and replaced the lot with just a 12 pin plug and add an anderson plug.
Interestingly, once the 13 Pin plug was gone I no longer got the "Check Left Tail Light" message so I reckon there is something to the suggestion earlier in this thread to add diodes. After saying that I reckon it is easier to just replace the lot with a 12 pin plug and be done with it.
The whole setup works perfectly now I just need to get VW to code the Tow Module as The Fizz mentioned in post #140.
 

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#146 ·
Hi Bill,
Love the HR hitch I wish I had that fitted. I had the OEM hitch and electrics fitted by the dealer with 13 pin plug tucked up way above the bumper with a 7 pin plug coming out of that......................
Great photos GazzaK,
I think you have finally convinced me to take the next step and get rid of the 13 pin Euro altogether, like you have done. My initial request to the Dealer when I was arranging for the Towbar, Electrics and EBC to be installed, was to have a 12 pin flat. But I received dire warnings of what might and might not work, and the dreaded "Void Warranty" words were mentioned. With the benefit of information from this Forum, the fact that you have completed the changeover, and my own tinkering, I feel confident in going ahead.
I have to say; I love the Treg, great car to drive, beautiful fit and finish, fantastic economy, BUT, it has been an absolute pain in the butt to sort out the Caravan towing issues, and deal with the lack of transparency and difficulty in getting clear, concise information from VW. It almost makes me wish I had replaced my 2007 VRX Pajero with a brand new Paj for a lot less money. But I was intoxicated by the 550NM of Torque, and the prospect of having "the best towing tug in the business". I hope and pray that the reality lives up to the promise. And don't even mention WDH!!!! My head hurts.:confused:
 
#149 ·
Check trailer lights warning

Hi guys,
I have read extensively on here and other forums, and tested a few theories of my own, but have yet to solve this issue on my 2005 R5 sold in Australia.
I have a factory towbar and wiring ( 7 pin round ) and all three of my trailers have conventional lights, which are all operating fine. I have recently also installed a Prodigy P2 using the factory plug under the dash, which also works well. When a trailer is plugged in I get the blown globe warning light on the dash followed by the "Check trailer lights" message. I do significant towing miles and would love to get rid of it.
The factory harness only has 7 wires so I assume the diode solution cannot help me as there are no left and right circuits for rear lights.
I did get a bit excited when I found a loose earth near the right rear tail light but unfortunately no change.
Also disproved a theory that the car was expecting a reverse light.
I don't have LED lights (yet).
The only possibility left to me is that the country coding needs to be changed. Are the Australian dealers so incompetent to have missed this when the bar was fitted?
This may be the impetus for me to buy Rosstech.
Is there anything I have missed?
What do you all think?
Cheers.
 
#150 ·
I was going to ask if you have tried fitting a complete new set of light bulbs, but re-reading your post I see you have three trailers and so I assume the problem manifests itself on all three?
 
#154 ·
Hi

I recently bought an ex Japan 2007 3.6 FSI V6 that I drove from Auckland to Christchurch and love it. I want to fit a tow bar in CHC but the $2500 estimate from local dealer is just nuts. Has anyone found an installer here that can do the equivalent of an OEM (VW) wiring installation? I have looked at doing this myself with a kit from UK but it looks like you still need dealer to do recofig of car to make it work.

Any ideas,

Andy
 
#157 ·
You should be able to adapt any needed electronics by using a VCDS yourself - and since you now own a Treg you should have one available to you anyway.
 
#158 ·
Just been speaking with Gore Research in Adelaide who have a universal towing module which they claim can solve most Australian trailer wiring problems on ALL cars sold here. It has become clear to me that our wiring requirements are quite different to those in most other countries. Their module can be used on its own or in conjunction with a OEM module. Will see how it goes.