Corroded wiring (resolved)

[PeakRanger]

Hi all,

I've had my 2017 T6 panel Van for four years now and had more than my fair share of problems ! The latest was that the NS DRL light stopped working and flagged up a "lighting failure" This was diagnosed as corroded wiring and after arguing was fixed at VW UK's cost. A month on and I now have the bonnet sensor saying it's open when it isn't and causing an alarm trigger.

Has anyone else had wiring issues and in particular the bonnet sensor ... or is it just another common problem ?

Any suggestions on a fix greatly appreciated.

Cheers, Tim

 

[Loz]

I wouldn't say the bonnet switch is a common problem, but rodent damage comes up occasionally, but when you say corrosion, do you live on the coast?
Have you tried spray cleaning the bonnet catch/switch?

 

[PeakRanger]

I'm in Nottingham and haven't spent much time at the coast. I won't have chance to check anything until Sunday but will report back.

Dealer had to rewire a plug, unfortunately I don't know which one, to resolve the NS DRL problem.

Cheers, Tim

 

[PeakRanger]

So I looked at the bonnet catch micro-switch and unfortunately it's sealed so not easy to test without cutting the wires ! It clicks when you fool the bonnet lock with a screwdriver but the dash still shows the bonnet as open ? My hunch is that I have more corroded wiring so I plan to trace this back to where the connector is, which I think will be under the nearside front wheel arch.

To save me some time does anyone know which coupling point block it goes into ? (I looked in the VIP area for an "alarm wiring" section but couldn't find anything)

Finally, assuming I find some poor condition crimps, does anyone know their manufacturer and type or part number ?

Cheers, Tim

 

[Pauly]

It won’t be under alarm it will probably be in basic equipment or failing that convenience systems

 

[PeakRanger]

Thanks Pauly,

I found the F266 Bonnet contact switch within the Basic Equipment diagram. It connects to J519 Onboard supply control unit via T14 /10, presumably a connector, and Earth connection 7 (Main wiring harness) via Earth connection 1 (Front left wing harness).

Does anyone know where to find these particular locations and harnesses ?

I found the Coupling Point diagram which shows a big bank of connectors behind the NS headlight but how do I best access this area ?

Cheers, Tim

 

[Loz]

If you remove the starter battery, and then the cover of the e-box below, you will see 2 earth points, check them for corrosion (I would undo them and clean anyway whilst you are there)

 

[PeakRanger]

Thanks Loz,

I did that but sadly they were corrosion free ... I polished them with some Scotchguard anyway ! My only choice now is to locate the connector T14 which is detailed as near horn, does anyone know where this is and how to get to it ?

Cheers, Tim

 

[Pauly]

The horn is behind the offside foglight
It is possible to turn the steering to full left lock and remove the front and middle fixings for the wheel arch liner and you can pull back the front edge of the liner to access the foglight/horn area, other than that its a bumper off job

 

[PeakRanger]

Thanks Pauly,

I did exactly that and annoying found the dealer had made a crap repair for the original fault and only replaced some of the corroded crimps ! Needless to say I'm going to put in a complaint to VW (UK), there was even silicone bodged around it instead of the correct wire seals ... arrgghh

Cheers for everyone's help, Tim