is ther a walk through for changing rear Xantia wiper relay?

falling-out-with-my-car · Post by **falling-out-with-my-car** » 10 Jan 2010, 16:13

Hi,

Is there any detail please in changing rear wiper relays on the the forum please?

my estate wiper arm is intermittent at best and only seems to go when it pleases there has been no water running through the rear door for ages as I have applied a thin seam of body panel sealent along the lower rear screen rubber, it does work when you slam the door shut but this is a bit tricky whilst driving....lol.

I am guessing that it must be the relay sticking. can anyone enlighten me please?

thanks in advance regards Nigel.

DickieG · Post by **DickieG** » 10 Jan 2010, 16:18

An intermittent rear wiper/heated rear window is more than likely down to the wires breaking inside the rubber boots at the top of the tailgate.

Post by **CitroJim** » 10 Jan 2010, 16:32

It is easy enough Nigel, just remove the interior trim on the tailgate (plus membrane if an estate) and the relay will be accessible. It's a blue one attached to the wiper motor frame.

As Richard says, it'll more likely be broken wires, especially if it's an estate.

It's more that just a relay too, it contains electronics to give the intermittent wiper delay.

Richard, on that subject, I have not forgotten about looking at changing the delay interval on the relay. I still have it in front of me here on my desk...

falling-out-with-my-car · Post by **falling-out-with-my-car** » 10 Jan 2010, 16:33

ahh now that you mention that I did have some trouble with light wires inside the the rubber boot they had to be cut and soldered together, ahh you could be spot on there DickieG.

thanks for that, I'll check it out I bet the rubber boots are rock solid in this cold weather.

Thanks Jim I'll defiantely check this out, have you any idea which side contains the wiper wires please?

as i have two boots one at each side of the door?

regards Nigel.

spider · Post by **spider** » 10 Jan 2010, 16:42

Slightly off topic : The delay circuitry is probably just the usual relay and a 555 timer IC onboard or very nearby. It's probably possible to lookup a timer delay circuit (Google will provide plenty if you search for something like 555 timer etc)

Replacing a resistor with one of a higher value (typically) in the timer circuit will achieve what's needed. A small pcb mounted potentiometer may be best as then you can get it exactly as you require.

falling-out-with-my-car · Post by **falling-out-with-my-car** » 10 Jan 2010, 16:47

Ive just been out with a torch and wriggled the left hand side boot and for the fist time ever I have just been able to lock the rear door on the remote without getting beeped at by the alarm telling me the locks havent engaged properly.

Im going to check these wires out all of them it would seem that this might answer more than one fault in the end.

would be useful to know which side contains the wiper wiring though?

regards Nigel.

Post by **CitroJim** » 10 Jan 2010, 16:54

spider wrote:Slightly off topic : The delay circuitry is probably just the usual relay and a 555 timer IC onboard or very nearby.

No, actually, it's a special chip designed expressly for the purpose. A U642B.

Here's a data sheet on it...

Post by **CitroJim** » 10 Jan 2010, 16:57

Nigel,

I will consult my diagrams on the tailgate wiring and see which side it is...

Post by **CitroJim** » 10 Jan 2010, 16:59

Just consulted and the wiper wiring goes down the nearside (LH) concertina...

Post by **myglaren** » 10 Jan 2010, 17:02

Remember not to just mend the breaks in the wiring but to splice anew piece in, a couple of inches long, to reduce the stress on the wires that caused the break in the fist place.