Proposed wiper switch mod

[steve lyle]

This past fall I did a fair amount of driving through drizzle. The kind of rain where you don't need the wipers on at low speed for any length of time, just a sweep every minute or so.

In a modern car you can do that without taking your hands off the wheel, with a stalk (or my BMW has rain sensinig wipers and you don't have to do anything). In the Elan, you have to take a hand of the wheel, turn the wipers on at the dash, then turn them off again.

Meanwhile, the headlight control stalk has a mode that I don't use - pull it toward you, and it flashes the high beam. But flip it down, and it turns on the high beam, so a flash could just be flip it down, then back up. Leaving the "pull it to you" switch for some other, more useful, purpose.

I've currently got the dash out, oiling the heater motor, replacing the wiper wheel boxes, cleaning up my rewire job from last summer, etc.. So I'm thinking this would be a good time to make better use of the headlight stalk. There's a brown wire in the column wire bundle from the headlight stalk that goes hot when you pull the stalk. If I take that wire, remove it from the headlight circuit, and instead feed it to the wiper motor, it should activate the motor, as if I flipped the dash switch to low, correct? From the attached diagram it looks like jumping the brown wire to the R/LG wire somewhere between the wiper switch and the motor should take care of it. Am I missing anything? Just make sure that the brown wire can handle 1.5 amps or so? Add a relay if it can't.

[miked]

Done it. From my old post. Most satisfying long term upgrade thread, i think it was called. I will see if i can bump the thread. Bear in mind that a wiper motor is shorted circuited by the wedge switch at the end of the wiper throw to electrically brake the motion and generated back emf. So this park short circuit has to be opened before applying a pusle to move the motor onto the live park switch. If you google circuits for the old fashioned timed ones you will see how it is done. If i can find my book, i think i recorded it at the time.


Wipe using Light Stalk!
Last night I did a job that I think will be handy. Rather than fit a timed wiper control that you keep fiddling with, I made the flash function on the dip/main beam stalk to carry out a wipe. It has been discussed before about making this work. I pulled the standard switch out to find a 4 wire device with flash function throwing a positive signal in the dip position. So you would need to have the light wedge switch (fully) operated and side lights on (if you did not pull the vac switch). Perhaps no bad thing having side lights on in the rain?
Looking closely I could have carefully cut the link and soldered an extra wire to create an isolated independent switch. However, looking in my spares box I found a 5 wire stalk unit with separate flash circuit. Using this I powered a relay with changeover contacts (common, NC and NO). Using just 3 wires you can break the park circuit on the dash switch (electric brake) and feed a low speed positive. When operated this flick puts the wiper motor onto its park circuit supply to complete the wipe. So now, without taking my eyes off the road I can give a swish by just a pull on the stalk under my hand.
In the past when I have fitted timed controls they have had two relays or two switches. One for breaking the dash park circuit and one for the pulse to power up. It can however be done with the single relay.

Mike 

[steve lyle]

Thanks, Mike. I think maybe you've convinced me that this mod is over my head - since I didn't understand about half of your post. What I think I did understand is that it's not as easy as I thought.

What's a "wedge switch"?
What's a "relay with changeover contacts"?
"Using just 3 wires you can break....", crap, I didn't understand that either...

[mikealdren]

Spyder convert a stalk from a modern Mini as an (expensive) option for their Zetec cars.

[TBG]

I have done something similar. An old starter button wired up to give a single wipe.

[Craven]

I looked into the idea of using the pullback function on the main/dip switch many years ago but found the switch was hard wired internally such that the connection made, was between the main beam feed and the pullback contact, so not an isolated pair of contacts.
Recognising the shortfall in the wiper function compared to modern cars, I designed an arrangement that provides, using a VW wiper relay, wash + 3 passes of wiper, intermittent, slow and fast wipe.
Wiper control switch looks like standard on the dash, turn anti-clock gives wash/wipe clockwise gives intermittent, normal wipe and then fast.
FWIW.

[c.garde]

Gents and nerds,

I enjoy this thread. Cravens suggestion is quite elegant.

A reader is complaining of " way over his head". Have been there , in fact I am there constantly.

However why not keep it simple by incorporating the two combination stalks from late minis and various other models .

I went that road and am very happy with these two multistalks from early seventies..
However it was a very difficult conversion as I at the time did not know that late europas did exactly that.
a conversion to this set up is very straight once you have found the parts .

You may have a look at the parts catalogue from Banks Europa.

Best regards C.garde

[USA64]

I looked into the idea of using the pullback function on the main/dip switch many years ago but found the switch was hard wired internally such that the connection made, was between the main beam feed and the pullback contact, so not an isolated pair of contacts.
Recognising the shortfall in the wiper function compared to modern cars, I designed an arrangement that provides, using a VW wiper relay, wash + 3 passes of wiper, intermittent, slow and fast wipe.
Wiper control switch looks like standard on the dash, turn anti-clock gives wash/wipe clockwise gives intermittent, normal wipe and then fast.
FWIW.

Wiper Delay relays.jpg

Would it be possible to get that picture "with circles and arrows and paragraph on the back of each one explaining what each on was.." ? ( I know, that dates me).

[Craven]

USA64,
Sorry but don’t have the graphics to do that, but the larger of the units is the VW wiper control, this has output for the 3 wipe, intermittent, and continuous run.
Due to using a small current function control switch I used it was necessary to provide the other units seen, relays, for slow and fast wiper speeds. Also needed a further relay for the wash motor, draws 5 amps.
It’s the way in which the 2 speed motor with self park is done that requires separate relays.

[billwill]

I don't recall seeing any mention of the park switch shorting the motor before?

As far as I recall when I looked into this some time ago for a timed sweep mode, the park switch is OPEN when parked. When sweeping it is CLOSED feeding the power to the motor as an extra circuit along with the driver's switch. When the driver's switch is turned off the park switch continues to supply power to the motor until the blade is back in the park position. At that point the park switch opens so there is then no power to the motor and it stops.

All you need to do is to get the motor to run long enough for it to clear the park switch and it will then complete one sweep and stop when it gets back to the park position. The difficulty arises because the switch is done on the GROUND side of the circuit.



A single wipe "button" merely needs to connect the two sides of the park switch. i.e point marked RED to the point marked E (Car-body) or any other ground point.



The fact that the stalk switch is normally open ans supplies 12v at the operated condition is what needs a relay as an extra. The one end of coil in the relay (say #85) should be connected to the output of the stalk switch and the other end of the coil (#86) grounded, and the MAKE contacts of the relay should be wired as per the button mentioned above, i.e one (say #30) to RED and one (say #87) to ground.


Typical automotive relay connections:


If by any chance, in your car, there is a contact on the parking switch that shorts the motor (as shown in the diagram in the first message) simply disconnect it, It isn't needed, the wiper motor arrangement is not free running it is quite stiff and the motor will stop as soon as the park switch opens.

[TBG]

Bill - that is what my button shown above does. Works brilliantly and is easily to hand, D

[USA64]

Thanks guys, very helpful. I was able to copy and paste to OpenOffice for later study. There are some things, like how the differential works, that I can understand while looking at it but immediately forget when I take my eyes off!

[Craven]

Later on reflection then,
Quote miked “You only need to google the two speed circuit that was on lots of cars from the period. Full write up of the circuit operation under all conditions showing this function.

[miked]

Just like i said on my early post. Back emf, electric brake!
You only need to google the two speed circuit that was on lots of cars from the period. Full write up of the circuit operation under all conditions showing this function. Clever ain't it. The short comes from the wedge wiper switch. Lots of people don't understand the circuit and wire this wrong and wonder why they get another wipe as it runs back onto the live park circuit. Mind you lots have stiff wheel boxes to help stop it.

[webbslinger]

Getting caught in a 2 day drizzle prompted me to rig a one-wipe switch a couple of years ago. My solution is a switch on the column wired in parrallel with the low speed side of the wiper switch on the dash.