Intermittent wash wipe

sleepy0905 · Post by **sleepy0905** » Thu Oct 12, 2006 11:27 am

hi has anyone fitted intermittent was/wipe to the rear wiper on a BX saloon as they dont have a latching switch I think the estate has it but i would like to have it on my saloon TZS

jeremy · Post by **jeremy** » Thu Oct 12, 2006 11:40 am

I should think the easiest is to substitute the Estate switch. I'm not sure where the intermittent bit is though.

The aerodynamics are supposed to be such that you don't need it - had the same arrangement on my Scirrocco - and seem to remember cursing it most of the time!

sleepy0905 · Post by **sleepy0905** » Thu Oct 12, 2006 11:45 am

Tried just changing the switch before and nothing happens. Grrrr
It is just it is a pain when raining and you have to reverse onto a small drive with only an inch to spare on each side because of the gate posts and you cannot see out of the back window without having to hold the switch in while trying to reverse.

jeremy · Post by **jeremy** » Thu Oct 12, 2006 12:04 pm

Must be on the estate motor then - bit strange as it runs continuously when it washes and there must be a timer somewhere.

If you only want it when reversing the intemittent bit isn't really needed and an override switch would do.

Looking at Haynes I see thet there is a rear wiper relay shown. I wonder if this has the delay and is different from saloon to estate. If you're handy on the PR net you may be able to trace it.

I think there is a complicated wiring diagram for the Mk 1 estate on Bob Smith's site - don't know if this will help.

Haynes shows the relay with a symbol looking like a top hat in it. In the ZX book this symbol is described as a delay unit. Haynes also states that this unit is ' on the inside of the instruement panel, under the top glove compartment, towards the console' . . . .which is of course handy for those of us without top glove compartments.

I've got to move the thing shortly - and will have a listen for the relay.

sleepy0905 · Post by **sleepy0905** » Thu Oct 12, 2006 12:11 pm

thanks jeremy I will look on the bob site and see what i can do.

jeremy · Post by **jeremy** » Thu Oct 12, 2006 12:20 pm

I've had a look - difficult to hear the relay with the back wiper scraping and the washer running but it could be behind the instruments or between them and the central tray.

The motor has 3 connections only (I would expect to be power, earth and park override) - and doesn't look as though it has any electronics.

Geoffrey Gould · Post by **Geoffrey Gould** » Thu Oct 12, 2006 12:43 pm

Hi The simple solution would be a separate switch , possibly in the panel by your right knee. The press and hold thing was probably to stop the wiper from being "forgotten" and burning the motor out. With all the distractions nowadays when you have to have at least 3 pairs of eyes ( oh to be able to see like a fly, only kidding!!) it seems to be quite a possibity.
Cheers.
Geoff.

AndersDK · Post by **AndersDK** » Thu Oct 12, 2006 8:30 pm

The wiring to the rear wiper is the same being either saloon or estate, either push to operate or steady timed (intermittent) wipe.

The differences are in the 2 type of switches, the connector layout (pinning) to the 2 type switches, and the timer relay behind the dash. The timer relay is NOT fitted to the push-to-operate option - and wont make sense either.
However in both cases the washer is only operated while the switch is pushed and held in.

It is not possible to fit a simple toggle switch to have steady operation of the wipers. This is because of the rather complicated circuit between the operating switch and wiper motor stop switch. This circuit includes 3 separate wires running to the wiper motor, and a local earth wire behind the RHS lamp cluster.

A very common problem is the switch contact set failing to operate the washer. Sometimes it may come into life for a couple of years again if a relay is fitted to take the washer pump power.

I recommand an intense study of the wiper circuit diagram - as for the fainthearted (not so experienced) DIY car electrician - the wiper circuit really is much more complicated than you may think.

sleepy0905 · Post by **sleepy0905** » Thu Oct 12, 2006 8:59 pm

Thanks Anders and all I will be studying the diagrams to see what i can do as there are lots of occasions where an intermittent rear wash wipe would be a damd good idea.

Geoffrey Gould · Post by **Geoffrey Gould** » Thu Oct 12, 2006 10:40 pm

Anders I stand corrected, well I am sitting actually, that will teach me to assume that a simple switch would do. Should have known better - it is a Citroen!!!Sorry apologies if I mislead anyone.
Now to find an accurate wiring diagram.
Cheers.
Geoff.

Way2go · Post by **Way2go** » Fri Oct 13, 2006 12:58 am

AndersDK wrote: It is not possible to fit a simple toggle switch to have steady operation of the wipers. This is because of the rather complicated circuit between the operating switch and wiper motor stop switch. This circuit includes 3 separate wires running to the wiper motor, and a local earth wire behind the RHS lamp cluster.

Looking at this circuit, I cant see why you cant lift the wires as shown on the relay contacts and replace them with a simple toggle switch of the single pole double throw type. This would leave the existing switch for just the washer function.

Alternatively why not wire an electrolytic capacitor (with a series resistor) across the relay coil and this could give a longer operation of the wiper before it turned off?

If the relay is NOT fitted as shown then again the 3 wires can be lifted off the switch and wired again to a simple toggle switch of the single pole double throw type as they must be of similar format.

AndersDK · Post by **AndersDK** » Fri Oct 13, 2006 6:44 pm

Way2go wrote:
AndersDK wrote: It is not possible to fit a simple toggle switch to have steady operation of the wipers. This is because of the rather complicated circuit between the operating switch and wiper motor stop switch. This circuit includes 3 separate wires running to the wiper motor, and a local earth wire behind the RHS lamp cluster.
Looking at this circuit, I cant see why you cant lift the wires as shown on the relay contacts and replace them with a simple toggle switch of the single pole double throw type. This would leave the existing switch for just the washer function.
Alternatively why not wire an electrolytic capacitor (with a series resistor) across the relay coil and this could give a longer operation of the wiper before it turned off?
If the relay is NOT fitted as shown then again the 3 wires can be lifted off the switch and wired again to a simple toggle switch of the single pole double throw type as they must be of similar format.

You're right

I'd forgotten the function of a "toggle" switch - which exactly is to "toggle" between 2 different circuit connections - *steady* connected.
Thats in fact exactly how the dash switch operates - being either pto or mode "toggled" type.
I was thinking in terms "on-off" switch.

Sorry all.

*******
To confuse matters even more

- its possible to "move" the dashboard switch toggle function to the rear door next to the wiper motor.
This is done using a double acting ("toggling") relay.
(Which is a completely standard relay - having a closed contact set in rest - and another contact set closed when operated)
Thats how I did it to my Estate when I found out the dash switch was knackered.
The dash switch then only needs an an-off function.

Mike E (uk) · Post by **Mike E (uk)** » Fri Oct 13, 2006 10:51 pm

Ever since I bought my 1st BX, about 12 years ago, I have intended to fit an intermittant rear wiper circuit.

I plan to replace the wash/wipe switch with a spare hazard switch, to siwtch power to the wiper. Then add a timer so it wipes once every 10 seconds or so.
Another switch added by the window motor controls could do the washer function separately, or simply parallel it with the front washer.

One day I may actually get round to fitting it.

Mike

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