Intermittent Wipers

[David53]

Does anyone have a circuit for wiring intermittent (spelling??) wipers? My Series II (MM style dash etc) is a bit of a pain in light drizzle as the wiper switch is on top of the dash and awkward to pull on and push off continually. Would like to set up intermittent wiping - is there a kit or something for this?

[alex_holden]

Here in the UK a company called Velleman does a kit that you can buy from Maplin:
http://www.maplin.co.uk/k2599-intermitt ... oller-3182

I've not built one myself so don't know if it's any good.

[chrisryder]

There is a kit i know of, but have had no experience of, for classic minis. It is a box of tricks that you wire in and with it activated, you wipe once, and then wipe again when it needs it, and it remembers the time elapsed and uses that rate for your intermittence. Theoretically that means that the intermittence is perfect for the conditions as you effectively set the rate each time. It sounds good, i'm not sure how much the kit costs, and i don't know if it can be adapted for a minor, but it's one option!

[bmcecosse]

The kits can only work if the wipers are self parking - I'm not sure if early cars have self parking ? If they do - it's just a case of giving the motor a short burst of power and then it 'self parks'. So a simple 555 timer circuit will do it.

[David53]

No, they are not self parking - so no way of making them intermittent?

[alex_holden]

Perhaps you could make them self-parking first? The tricky part would be fixing up a SPDT microswitch in such a way that it opens when the wipers are not parked. Supply the motor from the common terminal, connect an ignition switched live to the NC terminal and the feed from the wiper switch to the NO terminal.

[alex_holden]

Perhaps you could make them self-parking first? The tricky part would be fixing up a SPDT microswitch in such a way that it opens when the wipers are not parked. Supply the motor from the common terminal, connect an ignition switched live to the NC terminal and the feed from the wiper switch to the NO terminal.

Actually I've just realised there's a simpler way to wire it: leave the existing wire from the switch to the motor, and add the microswitch in parallel to the manual switch, fixed up in such a way that it powers the motor when the wipers are not parked. I think that's effectively what happens inside the later self-parking motors.

[mike.perry]

Agreed, getting the wipers to stop in the correct position and having to keep switching the central switch on and off in light rain is a pain.
By changing the switch for a light switch and fitting an electric washer pump to the switch you have one less switch to worry about and you can give the screen a quick squirt when you switch the wipers on.
Alternatively you may be able to wire up a delay to the spare terminal.
The other alternative is not to take the Minor out in the rain but with the weather you have been getting lately maybe that would be difficult.

[phurn]

Why not use a 555 and a jk flip flop to pulse power to the motor. Get the pulses right with some fine tuning and. Away you go

[alex_holden]

Why not use a 555 and a jk flip flop to pulse power to the motor. Get the pulses right with some fine tuning and. Away you go

Adding a flip flop to the timer doesn't solve the parking problem.

[phurn]

No but you can control the length of pulse, therefore determine where the wipes stop, like an automatic way of pulling the switch in and out

[alex_holden]

You can do that with just a 555, but I think it will quickly get out of sync because the speed of the wipers varies so much depending on how dry the screen is, how cold the grease is, the state of battery charge etc.

[bmcecosse]

Exactly - on a wet screen the wipers go faster than on a dry-ish screen. It would drive you mad stopping in all sorts of odd places. Simplest would be to fit a later self parking wiper motor. Then the 555 timer will work.

[phurn]

Yeah I hadn't considered the differing speeds =\

[David53]

Thanks for the advice - it all sounds a bit too hard for something which is really only an annoyance as opposed to a major problem. I'm not sure the later motor option would work, as the early cars have the wiper motor in behind the dash, near the speedo and I think ( though I may be wrong) that it is a slightly different motor/size?

[bmcecosse]

Any chance of a picture of it ?

[David53]

Hmmm...prob not. It is positioned behind the dash on the far right, hard to get a camera in there.....could try. Mike do you have a pic of it?

[mike.perry]

'Fraid not and I have absolutely no intention of grovelling under the dash again to get at it!
P.122 of your manual has a diagram and here are a couple more[frame][/frame][frame][/frame]

[katy]

A simple push button, in a convenient place, wired in parallel to the on-off switch would allow you to start the wipers and stop them wherever you want.

[bmcecosse]

Looks pretty much like the later motor with parking..... Very likely would be a straight swop I think!
You would need to hold the push button down all the time......