The rear wiper on my son's car no longer works when the Hatch is closed, but strangely if you open it above horizontal and try the wiper again, it works.

 

Anyone got any ideas

That will almost certainly be a faulty rear hatch sensor switch - does the trunk light work?

Not just a sheared wire between the car body and the hatch?

 

Ie wire sheared but making when the hatched is open/partly open?

Apologies for delay in replying - long story

 

The issue turned out to be as Rum4mo suggested - a wire had broken in the loom contained in the concertinaed rubber sleeve between the hatch and the cars main body. I ended up splicing in a new short piece of wire using a soldering iron and heat shrink. Worryingly most of the other 7 or 8 wires showed significant cracking to the wires plastic insulation sleeves so tried to add protection to them with heat shrink. Clearly the quality of wiring used is not up to the 

I'd reckon that the only way for VW Group - and others, to stop that happening would be to make sure that the type of wire and its insulation, for the short run from the car to the hatch, was more robust AND flexible - and they and others will not be interested in doing that - there must be a solution for this sort of issue, even some SAABs fell foul of this issue, as did or maybe still do, Ford.

Many. many years ago at some show or other there was a Jag on a stand about alternative to copper wiring (forget what) for car wiring as the amount and weight of the wiring on such a luxury car as this with all of its comforts and conveniences (mostly completely standard on poverty-level shopping trollies now) was so much at the time that it was thought something needed doing - obviously it was thought best to make the wires and insulation a lot thinner. 😆

 

(By SAAB I expect you mean GM SAAB.)

 

13 hours ago, nta16 said:

Many. many years ago at some show or other there was a Jag on a stand about alternative to copper wiring (forget what) for car wiring as the amount and weight of the wiring on such a luxury car as this with all of its comforts and conveniences (mostly completely standard on poverty-level shopping trollies now) was so much at the time that it was thought something needed doing - obviously it was thought best to make the wires and insulation a lot thinner. 😆

Yes, in the distant past I probably used Halfords etc sourced reels of "auto wire" which really did have thick insulation - as well as being  "correct for that load" c/s, then maybe 8 years ago I retro fitted front parking sensors to my bought slightly use Audi S4, as part of that job I got wise/lazy and bought in Kufatec cable sets specific to that task, the insulation was extremely thin - but that is standard now on newer cars, so when I needed to "adapt" these prefabricated cable forms to neatly/correctly suit that car, I bought in exactly the same "grade" of wire - certainly it doesn't waste any space!

13 hours ago, nta16 said:

 

(By SAAB I expect you mean GM SAAB.)

 

      Sigh, unfortunately so!  They certainly "did a good job" on SAAB, I remember when my SAAB mate bought his wife her first used SAAB 9-3 and I was frowned on for spotting that the "grab handles" looked exactly the same as the ones on my Cav 2000 16V GSI 4X4 - no surprise there I suppose!

My SAAB mate still has that affliction - but currently just a single 96 and two 900 convertibles, ie CC - all the many previou 95s, 96s, 9-3s and 9-5s saloons and estates used as daily drivers have been recycled! VW T-Roc is his present daily driver.