UK-POLOS.NET - THE VW Polo Forum

OK, will check the demister again in the morning when the frost comes down.

Nope, there are a few Valeo units on the 'bay for around twenty five notes.

Would there be any point in removing the old unit first to check (it seems highly suspect)?

Maybe a quick cheap and easy test, if you have a set of jump leads or even a length of heavy wire, connect one end to a good clean earth point in the rear of the car’s body and the other end of it to a good earth or clean metal point on the hatch, preferably on the inner side of it, then check demister and wiper motor operation.

I’ve forgotten, but does the rear hatch lock work, and can you pop it open from the remote?

Thanks for the suggestion RUM4MO. I'll get hold of a jump lead and try that. I have the tailgate trim off at the moment. I got the tailgate working again on central locking some time ago (another thread) and it was locking/unlocking. I've not noticed since whether that is still working or not. I'll check that too.

Just another thought on potential electrical gremlins. On the rear o/s the fog lamp sometimes comes on with the rear o/s position light. Though that's probably a fault local to the rear o/s cluster assembly. All other lamps work OK, as does the rear washer jet.

Water getting into the cluster or down onto the connector strip which is only steel mildly plated with zinc - horrible and cheap design, contacts really too heavily sprung for use with bulbs with lead solder on their contacts, just nasty in my mind!

Just wondering if a rear wiper motor fault would show up at all on a diagnostics scan tool?

It would need to be a proper VW Group compliant scan tool like VCDS - but to be honest I would not expect that even VCDS would reveal much, just lots of investigating needed - sorry!

The rear demister has started working again. Polo electrical gremlins. The only thing I had done was to remove and refit the tailgate trim either side of the demister element. Will check the wiring over thoroughly at the weekend and monitor.

Plan to remove and check the rear wiper motor for seizure/failure at the weekend too.

viewtopic.php?f=8&t=72450&p=547402#p547402 maybe useful for you!

RUM4MO wrote: ↑Fri Jan 04, 2019 10:00 pm I’ve forgotten, but does the rear hatch lock work, and can you pop it open from the remote?

I'd forgotten too. I thought it did but when I unlocked the vehicle this afternoon the boot did not unlock and I had to resort to the key. The tailgate lock had worked after I removed the tailgate trim and reattached the lock/plunger assembly.

So now:

1) Rear demister works
2) Rear wiper does not work (but there is a voltage present at the motor power connector)
3) Tailgate lock does not open when unlocking the car (with a key as it has no fob).

Last job I remember doing in early summer was fitting a dual camera, but I ran the cable around the headlining and under the trim at the back of the headlining next to the tailgate. The routing was from the offside and nowhere near the gaiter on the tailgate nearside.

Could earthing be an issue?

I seem to recall if the boot micro switch is faulty and it thinks the boot isn’t closed the wiper won’t work. Not sure if that was on this model though or newer ones

Similar to the sudden recovery of the warning buzzer when the lights are left o(other thread) the tailgate now releases with the central locking. Since the rear demister and wash-wipe is working that leaves only the rear wiper not working. With a voltage at the motor itself it seems the motor is likely faulty so will proceed to remove, check for siezure, and replace if needed.

Did you pull back the rubber boot and check the wires between? I had a golf in for work this week and it had exactly the same problem. Two broken wires in the rubber tube on the left - repaired with a new section and problem solved.

Not yet. One fine sunny day soon.

Cool, gently does it. Easy to tear, so pull from the base

Is there any slack in the wiring bundle to play with?