Oops, offer open to anyone, of course...

I'd still like to recommend swiping the relay out of something modern, it'll be no harder to fit than an aftermarket job, won't involve any soldering, and it's far more satisfying to use something that was otherwise going to the crusher. Only minus point is that you won't get the variable intermittent function unless you can find a donor with it, there are some, my rear engined skoda had it!

Finns have made these quite long. I´m not a clever man with these things, but i can ask, if they can explain it in your language...

that velleman PCB you show Dago is the exact one that maplins sell (or would see if they had any)

Ive got one at home still, never fitted it though.

Yeah. I do not have one, allthough our club here ín Finland had few of them.

The basic idea is to have an 'astable' circuit - basically a timer that will give out regular pulses of elecktrickery. The Maplins-type circuit shown above uses, I believe, a 555 timer chip which is a cheap and simple fellow. A 'Potentiometer' (variable resistor) allows you to alter the timing of the pulses given out.

These pulses then trigger a relay, which closes its contacts every time it gets a pulse. A relay is needed because the wiper motor draws a hefty current, far more than the 555 chip can deliver on its own - it would just fry...

The contacts of the relay (just two are used: 'Com' which stands for 'common' and 'N.O.' which stands for 'normally open') are wired, I understand, across the normal wiper dashboard switch terminals, in parallel with them so that they also operate the wipers.

The idea is that the timer - when switched on - gives a series of short pulses of perhaps a half second long (with longer 'off' gaps in between) which closes the relay for this short pulse time and is enough to just get the wiper motor moving. Once it starts moving, its normal built-in 'parking' switch will keep it going until it returns back to the park position - it should do a complete sweep. It'll stop there parked - until it gets another 'pulse'!

So, the timer circuit needs to delver short, half-secondish, pulses with a delay between them of AT LEAST however long the wipers take to make a full 'sweep'. (Mind you, if it pulses faster than that it won't make any difference - any pulses whilst the wipers are moving will have no effect.)

Glad you asked?

Oh, you didn't ask...

Thanks DA, I found that interesting.

Thats very helpful, thanks.

Well the plan was is to have intermittent wipers on the GS using a standard 2cv wiper switch mounted up by where the fan switches and hide the relay up somewhere. If it was easy and cheap, Ild do it to my Dyane too.

Would it need just a relay? From Dago's picture it shows 4 connections going to the relay so I imagine that could be a standard 4 pin relay for spotlights etc... Citroens have a 6 pin relay for the wipers, we had to change 1 on a Saxo where the intermittent and park didnt work so I imagine the intermittent is built into them?

http://cgi.ebay.co.uk/Peugeot-806-Wiper ... 3a5494bbe1

Joolz - yer sad...

MCRJack, a 'relay' on its own won't do anything. I don't know whether the 'relay' shown in the ebay advert also contains the timing circuit - it might, or it might not. I just don't know.

Dago's useful circuit diagram doesn't show a relay either - it's just a diagram of a car's 2-speed wiper wiring system, and also shows the 'self park' switch.

Relays can have a few purposes in life, but the one in the wiper timer delay circuitboard also shown in Dago's post above (the Maplin's kit) has a simple job - it acts as a switch which is wired across the normal wiper switch to 'get the wipers going' whenever it's given a pulse. If you can imagine pressing the existing wiper switch on your 2CV for a brief moment - it's enough for the wipers to 'get going' and give a single full sweep before parking again - waiting for another 'pulse'.

(The 'Com' and 'N.O.' pins of the relay I mentioned before would be connected to 15 and 53 on that diagram. It would briefly 'join' these contacts together to get the wipers moving.)

In Dago's diagram, switch 'P' is the parking switch. This is fitted inside the actual motor housing. Its job is to always get the wipers back to the park position - there is a contact inside the motor housing which only 'opens', cutting the power, when the wipers are in the 'park' position.

So, I've no idea if MCRJack's ebay relay will do the job. I suspect it either won't, or - if it will - it'll be tricky to wire up! Just guessing there, of course.

I think the best bet is still to track down an after-market delay kit like Maplin's. Looking at my 2CV dash, the rotary control would fit neatly down the RH side of the dash - virtually out of sight, but easy to access.

Yep and unashamed of it.

It sounds from Jack's account that that ebay 'relay' contains the whole lot, either way it's about a quarter the size of the renault relay/control box I fitted, which had a big multi plug with about 7 or 8 wires, and I have to admit, did have me scratching my head for a while.

If that maplins kit just fits in parallel to the original switch, then it sounds like a much easier option, and £8 won't exactly break the bank.

One thing I still don't quite get is why the standard circuit for dual speed wipers is so complicated, why the second set of contacts in the switch. Could the parking switch not connect the live feed directly to the motor input?
I can see several functions that the extra switch achieves, earthing the motor feed when the switch is off and the wipers are parked, and preventing both speed feeds being live at the same time when on fast wipe, but I can't see why that would be necessary.