Jack, Joolz et al,
back to those VW types again...
< http://www.keithandsylvia.co.uk/tech%20 ... wipers.htm >

I'd be having a look in our local scrapyard for any '82 to '90 VWs if this is as easy as it seems, for the early 'pepperpot' wiper motors at least.

Btw, many of the intermittent wiper relays are programmable, from what I've found on a quick trawl of the net, so it may be more complicated to install one of those.

ken

Some of those VWs etc had the variable relay in place of the "normal" fixed interval one - but they're just a straight swap - and into a multitude of other similar-era cars, including s2 CXs and Saab 900s...

It's a fantastic upgrade - I did it to the Saab a while back, and now rarely use "full" wipe - just program the relay by flicking,intermittent on-and-off, pause, then put intermittent on. Sorted. Job jobbed. If you want to re-program, intermittent off - and you get one wipe to time by. Then back on to intermittent again after the right delay.

A bit more...
http://www.saabcentral.com/techhelp/c90 ... wipers.php

Hmmm clever, so who's going to try and fit one of those then?

Ah! Wait a minute!!! That Bug 'intermittent' wiper thingy ain't the same!!!

All that does is allow you to have a single sweep of the blades by pressing a 'push-to-make' (ie: a type of switch that doesn't stay on - it just makes contact as long as you press it - like a 'horn' button) switch whenever you want a wipe.

Jeepers, if that's all you want, then easy-peasy! Just get yourself a suitable switch, mount it where your fingertips can get to it easily, and wire it to terminals 15 and 53 on Dago's diagram (or just across the normal wiper switch on your dash.) Provided the switch is 'heavy-duty' enough, you don't even need a relay. All it'll do is give you a single wipe every time you press the button - it ISN'T an automatic variable wipe delay.

The Maplins circuit can be switched on to give you continuous single wipes with a variable delay in between each wipe for as long as it's switched on, keeping the screen cleared during light drizzles, etc. - surely what we are really after?

If Maplins ever gets them back into stock, I'm getting one!!!

Joolz - I see what you mean about that switch!

Blimey, it had me scratching my head, but I think I know what it's about.

When the motor is running, the 'park' switch 'P' is making contact with '1' except at the end of the wiper's travel - when it breaks contact and goes to '0'. As you clearly know, this means that the motor will keep on running to finish a sweep even after the main switch is turned off.

Now, the clever thing is that, with the main switch off, and the wiper finally reaching the end of its sweep and P goes to back '0', if you trace what is happening you'll see that the park switch and the main switch are allowing the motor to 'short circuit' itself - you can follow the wire from one side of the motor all the way around to the other side!

Why? Because this causes electrical braking, which brings the motor to a much quicker halt. Without this, the motor would 'wind down' relatively slowly which would allow it to over-run and get the park switch making contact again - it would look as tho' it was coming to a halt, but would pick up again - ad nauseum!

Now, does that affect how we'd connect our yet-to-be-built circuit...?

Jeepers, yes it would - on that circuit at least! If I were to connect my realy contacts across 15 and 53 as I said before, it would cause a short circuit across the power supply! I think what would need to be done would be to connect it across the 2nd speed - ie: 15 and 53b - and this would get the motor running as before.

I daresay, once we get hold of a Maplins circuit, it'll make it clear how it should be connected.

Does this apply to a 2CV's single speed system? I dunno - I haven't seen the circuit diagram

By the same token, what I said earlier about just fitting a push-to-make switch across the 2CV single switch to give simple one-touch intermittent wipe is complete bawllocks At least if it's wired anything like the 2-speed setup.

All it would give you is a quick 'flash' - and not the kind you want.

Probably explains the use of the relay in the 'Bug' circuit, tho' I don't find it easy to follow as it doesn't show what the terminals of the actual relay are.

Jeez - my head hurts...

Just press the normal 2cv switch part way in, so it doesn't latch on.

That's wa-ay too hard

Are you saying my wipers are meant to complete their sweep and park? Bugger I might need to check the system before I attempt an intermittent wipe install