Wiring for towbar query

[arizmanor]

I have been chasing around the local towbar installers and it looks as though there is a choice of wiring methods. There is the cheap where the older normal method of using Scotchlocks is used, or utilising a VW wiring loom to just plug in to the car's system. I have been given the understanding that this second method requires me to then go to the VW dealer to have the system reprogrammed for something like £100.

Since I am an old newbie (who has fitted towbars and the electrics in the dim and distant past), I have no experience of the recent developments in wiring techniques and systems.

So, since I only need to pull a trailer, will the cheap way be satisfactory or will there be issues I ought to be aware of?

[PFJones]

I have been chasing around the local towbar installers and it looks as though there is a choice of wiring methods. There is the cheap where the older normal method of using Scotchlocks is used, or utilising a VW wiring loom to just plug in to the car's system. I have been given the understanding that this second method requires me to then go to the VW dealer to have the system reprogrammed for something like £100.

Since I am an old newbie (who has fitted towbars and the electrics in the dim and distant past), I have no experience of the recent developments in wiring techniques and systems.

So, since I only need to pull a trailer, will the cheap way be satisfactory or will there be issues I ought to be aware of?

Hi ArizManor,

You are right there is a choice, you have the option of splicing the electrics with scotch locks as you said, the next option is the plug-in wiring kits

We will be able to supply the wiring kit you need at towbar wiring kits
if you need any advice you can give Brian a call on the free phone number listed in my signature.

Scott
P.F.Jones

[arizmanor]

Thank you for your quick reply, but it didn't answer my question, which was does it matter if the 'old' method of wiring the 7-pin plug is OK - or will there be problems?

It would be nice if I might get an unbiassed view, but I have a feeling in my water that anything you say would be partial and slanted.

Also, would I need to spend another £100 os having my vehicle re-programmed if I decided to take the made-up loom option?

[bobble293]

Hi,

May have missed the info in your posting, but, if I can, I'll help. I have a B5 Passat, and have fitted a towbar, using the Scotchlok method. I agonised for ages before doing it, and looked everywhere for the info. If you have an early Passat (mine is 1999 "T" ) you can do it. If you have a later one, with CANBUS electrics, use the proprietary loom, which allows the car's computer to sense the presence of the trailer. You may have electronic stability control which will perform differently with the trailer attached. Don't know if the box of tricks needs to be reprogrammed as well, but that could be done after you've fitted the bar.

Mechanically mine was an easy fix. Bumper off, alloy bar removed, towbar in its place, no holes to drill, all done by VW, just bolt together. One 1/2" hole for cable (just a 12N for my trailer) prime raw edges of drilled hole. Scotchlok wires, pick up power for bulb failure buzzer. Easy on my 1999er. Buy a good bar, my one, german made, but swan neck's at an annoying angle about 5 degrees from vertical. Supplier didn't respond to complaints. strong enough, just annoying.

[Ben]

if it is a little box trailer the type halfords sell, then you will be alright with a multiplex bypass relay which utilises the scotchlock method. anything heavier like a horse box or caravan, opt for the vehicle specific wiring.

see my thread about fitting my towbar to my mk5 golf. all the information you need is in that thread.

[PFJones]

Thank you for your quick reply, but it didn't answer my question, which was does it matter if the 'old' method of wiring the 7-pin plug is OK - or will there be problems?

It would be nice if I might get an unbiassed view, but I have a feeling in my water that anything you say would be partial and slanted.

Also, would I need to spend another £100 os having my vehicle re-programmed if I decided to take the made-up loom option?

I understand your skepticism, I did not read your question properly the first time. Splicing the electrics is fine, if you tell me what model of VW you have I will be able to give you more info

If you want to know what the benefeits of each are I will tell you

Scotchlocks

Pros
+ Cheap

Cons
- Requires knowlege of vehicle electrics
- Risks frying the on board systems
- Voids any warranty you might have with a dealership

Plug-in Kits

Pros
+ protects the on-board systems
+ Does Not void any warranty
+ Activates T.S.P(Trailer Stability Program)

Cons
- Requires knowlege of vehicle electrics
- The kit is expensive
- Some makes of vehicle require a dealer download(which yes depending on the dealership they might make you pay up to £100)

I really have tried to be impartial. It is all down to personal preference really, if you are driving a 10 year old car then a plug in kit is pointless the cheaper option makes sense.

If you are driving a brand new fresh out of the factory, the paints still tacky VW passat then the plug in kit looks a little more attactive when you find out the dealership wants you to pay £1000+ to repair the on board computer(if it goes boom).

Scott
P.F.Jones

[pag]

Hi.

I have read this thread with interest as I have just acquired an '03 Passat TDi estate to use as a workhorse, (as well as the family car) and am about to fit a towbar.

I hate scotchlocks with a passion and rather than cut into a loom prefer to join into the vehicles wiring within the light units.
I remember a Jetta I owned long ago that had spade connection points on the light unit back plates but I suppose things have moved on from that design now.
I will find out no doubt when I start the job.

Cheers,
Paul G

[bobble293]

Hi,

Your vehicle has, I believe, Canbus, so, I think, will require specific plug-in wiring to avoid expensive problems. I'd checK before installing wiring system.

P.S I'd like a similar vehicle, do you mind telling how much? VW second hand prices seem high at the moment, as are Skoda equivalents.

Bobble.

[pag]

I've just been on the phone to a local main dealer who looked up my cars reg and said, quote:- "Your lucky mate. You can fit single electrics and you shouldn't have a problem."

I'm guessing that it's because I don't have the reversing sensers fitted.

The towbar company (on eBay) that supplied the bar (Bosal Swan Neck) sent it with a single socket, buzzer and Scotchlocks, no relay. The Scotchlocks are already in the bin.

So it looks like £84.50 and "jobs a good 'un."


Hi Bobble.

I think that the value of an oldish car is more to due with mileage and condition. Better to buy a well looked after older car that's just had the belt done than to look at the reg plate.
I looked at some dogs. One even smelt of dogs and had a white hairy floor to prove it.
You just know when a car is right the moment you first see it, and subject to a look through its history, and a test drive, you make a sensible offer.
Good luck
Paul G

[martin1810]

An 03 passat does not have can-bus wiring. You should find suitable connectors on the light units so you don't need scotchlocks. It only takes a few minutes to solder the wires if you choose to do it that way. No vehicle programing is required. Run everything through a 7 way bypass relay. Feed the relay from the fuse box or battery.