Hello people! (2019 Duster Mk 2 1.6Sce 4x4)

My thoughts are there is possibly some 'logic' box up the yingyang or the switch at the stalk is faulty.

The 'logic box' is the UCH/ BCM module.
Regarding the reverse wipers, the front ones are not really off, as u say that they may work @ random w/o any input.

 

I found it stressful that the rear wiper often sweeps without a command from the stalk when reverse is selected. Specifically when the rear screen was iced-up.

 

Does the fast work? The fast is directly wired through an extended winding the intermittent and normal speeds are initiated with a pulse from the UCH and completes the sweep on internal contacts. When you turn fast off you go through normal and intermittent which brings the internal contacts into play. Everyhing points to the internal contacts in the gear housing.
A bad case:-
View attachment 38373

The auto rear wipe is initiated if the front wiper is on or has recently been on. There is a timeout but I can't be bothered to find out how long. So I would ignore the rear wipe until you have fixed the front.

 

Hmm.. not a pretty sight, that's how I saw ours ending up. I wrapped it in Denso tape and paste.

 

Some interesting replies there! Thank you all very much 🙏

dralexandertom - I don't know what a UCH/BCM Module is but will look it up

Taf - I'm definitly with you if the wipers move when iced-up. This leads to the concern of unlocking the car in icy conditions and the front wipers moving - which they are doing (sometimes)

Daedalus - A very good point - I don't think I have actually tried them on the 'fast' setting. Although the other day when they just stopped - I was operating the stalk through all detents and nothing worked... then they did, eventually 🙄
Must give that a go and see what happens.

This afternoon I had to make a 1.5hour journey and, driving into sun, noticed the windscreen was very dusty, so (at a moment when I was driving in shade), I used the windscreen wash/wipe, and luckily they worked as they should ...although I notice the 'park' is a bit inaccurate, as if its going to do another sweep, but doesn't.


Thanks again to you all for a speedy responses.

John Auldford - I had found that picture while trying to search the forum for answers. Yes - that looks pretty grim, and worth investigating. Thanks 👍

 

The home position is determined by those contacts. It probably was going to do another sweep but failed. That is why they work unexpectedly, something causes the contacts to make.

 

Thanks Daedalus. Its going to be a while before I can get on to this job, but if/when I can get to the bottom of the problem I will report back