Jump to content

Variable Intermittent Wiper Modification

Recommended Posts

My 90 has the old 'single wipe down and two position two speed up' stalks and rather than go down the route of new stalk, wiring loom and programmable timer relay, I decided to look into a different solution.

The aim of the modification was to have the same stalk controls but also to have a variable intermittent wipe and this is how I did it,

You will need....

The Timer PCB

A relay and Base

A box for the PCB (I used a MB1)

A knob for the potentiometer (variable resistor) on order

Wire, heat shrink and soldering iron

This is the PCB, as it came, out of the packaging with the variable resistor on



For fitting purposes I removed the potentiometer from the PCB




Soldered the terminals with approx. 12'' of 11amp cable


Tidied it up a bit


Put some polystyrene in the box and fitted the PCB with a little mod to the board and box / lid for the cables


Prior to final fitting I wired up the PCB

Green - 12v (ignition live via a 3 amp fuse) and linked to common

Black - earth

Pink Signal wire to NO terminal

All 3 cables were 11amp

There was about 12'' of green and black and 24'' of the pink wire.


Then fitted the lid (no photo but I think you can all imagine a lid fitted?)

The PCB box was then fitted behind the centre console and the controller mounted in the front. The pink wire was fed to the dash area.


I then needed to wire up the relay which was a DPDT 12v type.

The operational control of the relay (power to the coil) was from the pink wire on the PCB board.

The other side of the coil was to earth

The terminals on the relay are supplied by cables on the wiper switch. (I modified the switch side of the cables rather than the harness side for two reasons - they are easier to get to and easier to put back to normal if this mod didn't work!) Obviously if my switch fails in the future then I will need to modify the new switch cables but that's something I will need to deal with at that time.

I connected a new green cable approx 12'' long to the green cable on the switch (cut, re-soldered and heat shrink) and did the same to the Red / Light Green cable.

I then cut the Brown / Light Green cable and extended both cut ends with the same colour cable (again each 12'' long)

Now on one of the throws of the relay (one set of contacts) I connected the Brown / Light Green wires to the common and normally closed terminal.

On the other throw I connected the Green to the common and the Red / Light Green to the normally open terminal


I know the drawings poor but I hope it's clear enough to follow.

The relay was mounted behind the speedo and everything put back together

With the ignition now on I can operate the wipers as normal or I can just turn the knob (when it arrives) on the variable resistor and I get an intermittent wipe at what ever delay I want from 3 to 30 seconds.

If I want to override the intermittent I just operate the wiper stalk as normal.

you will find a video which shows the operation of the modification

Hope this is of help to someone in the future but if you do attempt this mod I take no responsibility if things go wrong. I'm an engineer not an electrician and cannot be held responsible for any issues that you have.

If anyone notices any issues with my take on electrics, please feel free to comment.

Link to comment
Share on other sites

  • 8 months later...

Excellent post, a great solution.

However, there is an accessible solution for all us ham handed with a soldering iron.

There is a relay that does this when plugged into a standard wiper socket. Click intermittent on/off once, then wait a while and turn on intermittent. This measures and copies the interval (I think 1-30 seconds)

The one I have is DUDOCO - Interval Chip - 3579 0010 01

Here is a similar product - http://www.autopartswarehouse.com/intermittent_wiper_relay~pop.html

Mine was bought a long time ago for an Audi and works fine in my defender.

Link to comment
Share on other sites

However, there is an accessible solution for all us ham handed with a soldering iron.

There is a relay that does this when plugged into a standard wiper socket.

Mine was bought a long time ago for an Audi and works fine in my defender.

I got mine from my father's poor VW Passat, before bringing her to the scrapper with just 470000 Km on the clock :(

It was a five mins job.

Link to comment
Share on other sites

won't work on earlier vehicles because the wiash/wipe stalk is not the right type, but that can be replaced & with the unit you linked to can be made to work, done it on my 110 years ago, here's how http://forums.lr4x4.com/index.php?showtopic=927

the LR sub loom is no longer available but Autosparks can supply an alternative loom, for the same job.http://www.autosparks.co.uk/product_info.php?products_id=5128 no photo.

Link to comment
Share on other sites

I have one of simonb's rear wiper intermittent kits on my rear wiper, the relay needs modding to alter the timing between wipes as 3 secs on a rear screen is far to often, IIRC mine wipes every 40 seconds.but still wipes 4 times when washer is operated.see my post in link below

others have used this http://forums.lr4x4.com/index.php?showtopic=192

Link to comment
Share on other sites

  • 1 year later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


  • Create New...

Important Information

We use cookies to ensure you get the best experience. By using our website you agree to our Cookie Policy