http://www.velleman.eu/images/tmp/K2599DIA.jpg

(For future reference...)

Oh, now it looks complicated again

Thanks for that motor braking explanation, I've only just caught up, I had worked out what it was doing, but didn't know why.

It isn't really complicated - you don't actually have to know what that 555 chip does (although it's known as a 'timer'...).

What's interesting is that it has TWO output relays. I thought originally that only a simple SPST (single-pole - single-throw) relay would be needed - ie: one that acts as a simple switch - and that it would be wired in parallel with the normal wiper switch. In this way, either the normal wiper switch could be used as before, or else the timer is switched on and gives regular pulses to do an intermittent job. However, since being shown the rather more complex wiper switch earlier on - with that strange short-circuiting of the motor thingy - it seems more clear that BOTH relays will be needed with that type of setup.

However, I don't know what the modest 2CV wiper switch is like - does anyone?! Does it just have two wires going to it? If so, it'll just use two contacts from a single relay to make it work - relatively seeeemples. (Sorry... )

Some info I did get from the Maplin site was from their FAQs for this product. Apparently it DOESN'T come with instructions on how to wire it up to your car!!! And the timer adjust control is a 4-way rotary; OFF, 5 sec, 10 sec and 15 sec delays (I'm not 100% certain about the last two, it was something like that)

Anyways, I intend to get one at some point - these drizzly days really show how handy it would be.

And, yes, I have since adopted the 'slight'-press-of-the-wiper-switch-for-a-single wipe approach outlined earlier...

Shamelessly lifted from elsewhere:

http://cgi.ebay.com/ebaymotors/Intermittent-Wiper-Delay-unit-for-older-cars_W0QQcmdZViewItemQQhashZitem19b771922cQQitemZ110451855916QQptZLHQ5fDefaultDomainQ5f100

Yes, Adv, the 2CV wiper switch is a wire in and wire out for 12v supply. It is a single speed motor.

Aren't there 3 wires to the switch? One live feed, and two wires to the motor, one of which supplies power to the parking mechanism.

The switch has 2 wires. The third cable for the supply (+12) to parking position goes directly to the motor terminal from that fuse fed by the ignition key.


Regards

Luke and chicago,
I'd reckon you're both correct, because there were two types of motor...

The early (pepperpot) type has two wires to the motor and a switch with two connections.
The later Bosch motor has a switch with three connections, then there's a four-way plug connecting the motor to the loom.

Note that the above applies only to 2CVs, since other A series models may differ.
For example, some later Dyanes had the switch with 3 connectors, but there was a separate earth wire from the motor which needed to be screwed to the bulkhead.

ken
( p.s. @ chicago. If I'm not very much mistaken, you've got your wires crossed in the annotation of that picture. The 'park' connection, which is permanently live with 'ignition on', should be on the lower tag ;o)

Thanks gents.

This: http://www.2cvstuff.com/Files/Wiring/Wi ... t%2081.pdf seems to suggest the wiper switch does have THREE terminals, the third one being for the electrical braking of the motor as explained before. I haven't had a look at my own actual switch yet - they ain't the easiest thing to get a peek at - but I suspect it has three too.

Anyways, the Maplins unit has TWO output relays, and I guess that's why; one relay will use a pair of its N.O. (Normally Open) contacts, and will be wired across the original switch (to 'N' and 'Bl' in the diagram above) in order to get the wiper motor going. However, to prevent what would be a complete short circuit when this happens, you'd also use a pair of N.C. (Normally Closed) contacts from the second relay to simultaneously 'open' this potential short-circuit by having it wired into the 'Bc' wire going to the switch; this wire would be disconnected from the switch, connected to the relay, and a further link wire would continue it from the other side of the relay back to its original terminal on the switch.

So, whenever the unit gives a timed pulse, both relays operate for a brief moment - one closes to operate the wipers, and the other opens to prevent a short!

That's my best guess from scrabbling down a diagram!

I'll definitely be getting one...

I thought this forum was English only?