Mysterious intermittent rear wiper problem

[powerd]

Hi all

I have been a lurker here for some years but since my lovely 2011 Superb V6 AWD wagon (or Combi as you Euros call it) has been virtually trouble free since new, I haven't needed any assistance except with replacement of the alarm siren module.  BTW, ithe siren module was so much cheaper from Skodateile in Prague (SA95 posted vs $A450 at the local Aussie dealer!).  Only other problem was the need to adjust the striker plate on the wagon tailgate to fix a non-working rear wiper, done with help from this forum.  Thanks all.

 

Last year someone ran up the back of the car and among other things, the tailgate needed replacing.  It was adjusted poorly and the wiper wasn't working but as we were in drought it wasn't needed! (sorry to everyone in sodden UK etc).  But the drought has now broken on the east coast at least, with an absolute vengeance so I decided to fix it recently.  I accessed the striker plate and adjusted it upwards, got the tailgate fitting neaty and put all the plastics back on.  Went out in the rain and wiper wouldn't work but I stopped and just moved it with my hand slightly and voila!  No problems.  But since then, it won't work even with a nudge when I start up the car from cold.  But if I drive up the road for 500m-1km and get out and nudge it, it will usually!  And then it will usually work for the rest of the trip even if I stop and leave the car for a while.  But occasionally if I try the nudge after driving  it still won't work, but then it usually will restart of its own accord (if left switched on) later in a longer trip.

 

Any ideas on what to check so I can get it working reliably?  In electrical terms I am a bit of a numpty who believes electrons run on voodoo, so please make any electrical explanations simple!

 

Thanks in anticipation.

[chimaera]

When the tailgate was replaced, was the wiring harness in it replaced also, or was the original wiring swapped over? Ditto wiper motor and lock?

 

I'd start by checking for damaged/frayed wiring. Check that the connectors inside the rear headlining are snug. Also, check that the wiper motor isn't damaged: does it turn freely when you move it by hand?

[powerd]

Thanks for the suggestions chimera.  The tailgate wasn't badly damaged, just the lower right section mostly pushed in .  But replaced anyway.I doubt if the harness was replaced as there would have been no impact on it.

 

How do you remove the tailgate lining panel?  Or access the headlining area.   The wiper motor should be ok as most of the impact was taken by the bumper and no damage above the number plate at all, mostly below it in fact.  Wiper motor works fine once I can get it to start.  When I do try to start it, it only takes a tiny jiggle and off it goes.  You can't turn it if it isn't operating.

[Zukabak]

The tailgate liner just pulls off, it's held in place by incredibly annoying metal clips that are a pain in the balls to realign when you want to put it back!
Start at the base, working toward the roof of the car.. be careful it doesn't just drop though, as the two tiny lights in the trim panel are only attached by two very thin wires which can snap off if you don't have the weight of the panel supported when it drops.

[powerd]

Thanks Zukabak -  will try to pull it off this weekend.  Weather looking bad here though, but hopefully there will be a dry patch.

[powerd]

Didn't get an opportunity to work on it over th eweekend. 

 

But, mysteriously, it has now decided to work reliably and now starts as soon as you turn it on, even if the car has just started.  Perhaps it saw me writing about it on here and decided it ought to lift its game.......!

 

Thanks for th ehelp and I will keep my eye on it.

[chimaera]

Sounds like it might just have seized up a bit from lack of use.

[powerd]

I guess you are right.  We've had some more rain and still working fine.

 

Cheers

powerd