Rear washer on C5 Tourer

[Argos69]

I'd like your thoughts on my semi-logic please

So, the "ghost" that lives in the tailgate of my 2013 Tourer has made its presence felt again!

Some time ago, I was plagued by seemingly random activations of the rear wiper. Sometimes with washer, sometimes without.
I discovered that whilst the wiring over the tailgate hinge had no breaks, there were a couple of places where the insulation was cracked and there was water in the rubber tube.

I had removed the F1 fuse in the passenger footwell, to disable the rear wiper, until I (thought I'd) fixed it. All has been well after replacing the fuse, until 2 weeks ago, when it started again!

I checked the convoluted tube - all okay. So, as my Wife was grumbling about the wiper, I removed F1 again.
Now then, this is where the fun begins. The wiper has stopped, but the rear washer gives a blast of water periodically.
My understanding, is that the only electrical signals involved in this washing process, are in the vehicle itself (the front) and there is nothing relating to the tailgate.

By my instincts, it must surely be whatever is supplying the two way pump. Could this be the switch stalk and/or the Com2000 unit? If so, could this have been responsible for the wiper woes all along?

Needless to say, no codes or error messages so far.

[mickthemaverick]

That sounds a sensible piece of deduction. From experience in general I'd tend to suspect the Com2000 unit as the connectors to it can be iffy.

[wurlycorner]

Seems plausible, but could this also potentially be a confused BSI/water in the BSI or something like that?

Might be worth inspecting it and trying a BSI reset.

If it's the Com2000 unit then (if you're able) having Diagbox or similar running monitoring live data on the signals while you drive around, would show if it's being activated from that point, or not?

[Argos69]

I spotted on Fleabay, a complete unit with Com2000 and both lights and indicator stalks for only £25 in Lithuania (car recycling capitol of the world!).

So I thought "what the heck. for that money, I'll just buy it and try it out".

There is always a risk with these parts. I realise the number of variants on the wiper switch stalks alone is huge. I saw about half a dozen, all with subtly different markings to mine. I'm not in a position to dismantle to check part numbers as my Wife is away with the car at present. So I'm guessing the functionality would've been different on the other units. Anyway fingers crossed!

I'm also hoping that this will cure the car's annoying tendency to cancel the indicators half way round a corner or roundabout, but that would be a "nice to have" to be honest.

Thanks, I did try a BSI reset Wurlycorner and as it only happens when it feels like it, I couldn't drive around with my laptop & diagbox connected up.

I shall update when the unit arrives (2-3 weeks) and I attempt to fit it.

[Stickyfinger]

You say "cracked" insulation on the wire in the body-2-tailgate loom...........that is where I would look first, they are very thin and the moisture in the tube WILL get into them.
CAN works at low voltages, corroded wires could be causing these signal problems.......

[Argos69]

Hi Stickfinger and thanks.
When I originally exhumed the tailgate wiring, I wrapped any suspect areas in self-amal tape, before stuffing it all back in to the tube and self-amalgamating that too. I remain hopeful it's not that, but I'm still not sure how that would've affected the two way washer pump in the front, now that F1 is out.
I'll try anything, but I'm saving the process of chopping out all the tape until I've tried the new Com2000 & switches.

[Stickyfinger]

until I've tried the new Com2000 & switches

....which is more work than checking a couple of wires is it not ??

[Argos69]

"...which is more work than checking a couple of wires is it not ?? "

I'm certainly not going to argue with that, (although my self amal tape is set like rubber!). But I can't get my head around the possibility that the two way washer pump in the front wing, (with no wiring going over the tailgate) and being the current problem, is due to a tailgate wiring issue.

So, I'm going to wait until my unit arrives and fit it regardless. It's a cheap approach, as it's only £25 and my time is cheap (or so my Wife keeps telling me!). If it's no better, then the Stanley Knife is coming out!

[Stickyfinger]

But I can't get my head around the possibility that the two way washer pump in the front wing, (with no wiring going over the tailgate) and being the current problem, is due to a tailgate wiring issue

Because it is not "directly connected" to switches/controlled with signal/feedback signals via the CAN-B/COM system, thus it can be confused by faulty wires which can spike voltages (via water) or by voltage/earth drops etc.....

I understand what you are looking at with that type of tape however.....a brand new box cutter blade will be needed

[vallium]

As I've changed switchgear recently you need two different T20 bits - first long one for two bolts holding together the steering column cover and then very short to remove two horizontal bolts holding switchgear itself. Without the latter you’ll either have to remove the steering wheel or improvise with pliers & such. Normal 1/4" bit would perhaps fit with modification.

Otherwise it's really simple.

[Argos69]

I've taken my £25 Lithuanian Com2000 unit back to France, where the C5 has been sitting for a few weeks.

The sun came out today, so I bit the bullet and swapped the unit over. When I bought it online I "thought" it was identical (there are so many variations) and it does indeed have the auto functions and "mode" switch - phew! I've seen videos including removing the airbag and steering wheel and some leaving the wheel in situ. In the end I decided to give myself extra room and removed the airbag and wheel. Vallium's tip about the long Torx bit was right. Mine was 10mm too short, so I cheated using a flat bladed screwdriver
That centre wheel mounting Torx bolt was "criminally tight"! I have a really powerful impact driver and it took all of it's power! I'd not have achieved it using my normal socket set. The threads were coated in thread locking compound end to end!

The final result at whisky time, is that it appears to be ok. Everything works and the rear washer/wiper is behaving itself. But, as with all things Citroen, time will tell if my time and money was well spent. I shall update if anything changes.

Thanks for the help & advice.

[wurlycorner]

Glad to hear that seems to have fixed it.

[Argos69]

Thank you.

One final "mini whoopeee". Discovered today that the annoying tendency of the indicator to cancel halfway round a roundabout has gone as well! It makes sense, as I've swapped the indicator stalk together with the wiper control stalk, but it's something I'd not taken into account, as the wiper had been more of an irritation. Two things fixed!!! Knowing now how easy it was to do the job, I'd recommend it if you're struggling with the indicator stalk.

I'd love to say it's one of the few "blood free" jobs I've done on the C5, but I stabbed myself in the finger whilst freeing off a cable clip.
Hey ho, still worth it!