Electrical problems with VW Golf V towbar

**JandG** · 22-12-2006, 08:49 AM

Originally Posted by syncro

I'm at Picnic Point near the M5 toll plaza.
If you want to work out a time and bring the trailer over.
I work shifts and am usually home mornings.
email me at; plander@optusnet.com.au

Phill

Email sent.

syncro · 27-12-2006, 10:44 AM

Has anyone else here with a Golf 5 (or other can-bus car) had this problem?

It looks like UK and Euro trailer wiring has a seperate circuit for left and right tail lights and that's were the problem lies. To overcome this the VW 13 pin round Euro to flat 7 pin Australia adapter has two diodes to join the two tail lights together which causes problems with the bulb check function.

I wonder if there is an Australian software upgrade to rectify this

**JandG** · 03-02-2007, 09:24 AM

Been back to VW dealer several times now to sort this out. Went yesterday after they had told me they now have a "test box" to plug into the 7 pin plug to see if there are any problems. Guess what. It was bringing up the same fault as when I plug in my trailer plug.

Now they want the car for at least 2-3 days and will get in contact with VW to sort it out.

Can't believe what a drama this has been. At least they are convinced now that it is not my trailer causing it. Will post results after mid February when they have had the car. Have to say they are persistant and want to know what the problem is.
Gonna get a loan car. Hope it's a GTI!

Cheers

**MultiplexMan** · 05-07-2007, 02:44 PM

Hi JandG,

Did you get the tow bar sorted?

I am considering the towbar for my GTI but won't spend the money if the OEM kit has "issues".

Cheers,
MM

**njg02** · 05-07-2007, 03:03 PM

G'day guys.

I had the same issue a couple of months ago. Three trailers and one would not work on the golf. Everything worked on the T5. Auto electrician was at a loss and the local dealer pulled everything apart and changed modules and eventually found an earth problem. Check the earth if you havn't already.

Neil

syncro · 05-07-2007, 04:51 PM

The problem is that the VW wiring is not compatible with Australian trailers.

In Europe they have a left and right tail light circuit. In Australia they just have a tail light circuit.

homie100968 · 24-10-2007, 10:13 AM

Originally Posted by syncro

The problem is that the VW wiring is not compatible with Australian trailers.

In Europe they have a left and right tail light circuit. In Australia they just have a tail light circuit.

I have exactly the same problem as everyone else here...

Im an electrician and ill be ripping the whole car to bits if the dealership can't find a workable solution.
Ive been thinking about building a box with some high power transistors to switch the lights on and off .. which would isolate the trailer from the cars std wiring loom and "should" stop the idiot light telling me i got problems.
If this works it will mean the trailer lighting system wont cause the idiot light to iluminate even if the trailer has problems. But I dont have globes in mine anyhow.. All LED indicators etc... and all sealed so no water ingress to play havoc with earthing etc.
If I get this system up and running Ill let you know.. if not ill be buying a european loom to do it!

**LiFers** · 24-10-2007, 08:53 PM

Originally Posted by syncro

In Europe they have a left and right tail light circuit. In Australia they just have a tail light circuit.

This would be to cater for americans where brake lights are also blinkers.

homie100968 · 06-11-2007, 10:18 AM

Originally Posted by homie100968

I have exactly the same problem as everyone else here...

Im an electrician and ill be ripping the whole car to bits if the dealership can't find a workable solution.
Ive been thinking about building a box with some high power transistors to switch the lights on and off .. which would isolate the trailer from the cars std wiring loom and "should" stop the idiot light telling me i got problems.
If this works it will mean the trailer lighting system wont cause the idiot light to iluminate even if the trailer has problems. But I dont have globes in mine anyhow.. All LED indicators etc... and all sealed so no water ingress to play havoc with earthing etc.
If I get this system up and running Ill let you know.. if not ill be buying a european loom to do it!

ok so here goes...06Nov07
I pulled the right rear indicator assembly free from the vehicle and removed the globe carrier and then plugged it in to the wiring D connector..
tested for dc voltage and nothing.... tested for ac voltage and hey presto.. 5v ac ( @ 100Hz ) .. the indicator and parker (the inside globe) are both single use.. the outer globe is dual use .. but only 1 fillament... so its pulsed 5V ac to work as a parker and then (10-12V ? its brighter so must be higher voltage) V ac for brake light duties... so .... im guessing a smart relay will have to be employed to be able to get around the dual voltage tail / brake light .. im figuring on buying one from england and trying it out .. see what it can do.. all the other globes arent a problem... just that 1 brake / tail combo...

homie100968 · 14-11-2007, 01:14 PM

Originally Posted by homie100968

ok so here goes...06Nov07
I pulled the right rear indicator assembly free from the vehicle and removed the globe carrier and then plugged it in to the wiring D connector..
tested for dc voltage and nothing.... tested for ac voltage and hey presto.. 5v ac ( @ 100Hz ) .. the indicator and parker (the inside globe) are both single use.. the outer globe is dual use .. but only 1 fillament... so its pulsed 5V ac to work as a parker and then (10-12V ? its brighter so must be higher voltage) V ac for brake light duties... so .... im guessing a smart relay will have to be employed to be able to get around the dual voltage tail / brake light .. im figuring on buying one from england and trying it out .. see what it can do.. all the other globes arent a problem... just that 1 brake / tail combo...

Ok some more of the same..
Ive now found out the multimeter im using isnt reading the dc voltage because its pulsed !! hence the statement of having AC voltage..
Dc pulsed to the lights to change intensity of the globe.. hence being able to use a single fillament globe to get both park and stop on the one globe!!
my box of tricks is held up due to it costing more to ship than what the unit costs..!! So... I have been working on an alternative .. Im planing to try a voltage sensitive relay from Jaycar electronics to see if it can be employed to switch on for the brake lights.. Ill keep you posted.