Hi all, I have had my Jagaur 340 for around 18 years and until the other day everything worked fine, all the way down is off, first position slow, second position fast. Having not used the car for around two weeks, I turned the ignition on and the wipers started with the switch in off/park and will not stop! The first and second positions are as normal.
I know what your thinking, switch gone bad.... No changed the switch for a new old stock item and symptoms are the same. Ive investigated the wires going into the wiper motor after unscrewing the cap and the cable insulation looks OK.
All ideas / help appreciated - I cant find anything regarding removal of the wiper motor and what I might find inside?

 

could be anything like a faulty wiring plug at the motor itself, a stuck brush inside the motor, or intermittently going-bad motor, assuming the replacement steering column switch is fine.

removal of the motor should be found in the Factory Service Manual.

see if the attached Lucas PDF docs help to identify the motor, and in the second doc there is a test procedure to eliminate the switch or the motor as the problem, although not a very helpful procedure since you need to construct a test plug.

 

Jose, Thanks for your assistance and for copies of the Lucas documents, I will update after further fault finding.
Thanks again.

 

continue to drive into the rain

 

These Lucas screen wiper motors can drive you mad ! Essentially there is a constant 12v to the motor and it is stopped by a position switch inside the motor mechanism. When you turn on the wipers, this is bypassed. The position switch allows the wipers to return to rest when the driver switches off the wipers mid-wipe using the constant 12v supply..

So the answer lies in the motor not the switch on the dash

 

Gents, I stripped the Wiper motor out of the car in anticipation of a wiring switch nighmare and discovered the "Striker" that is brazed or welded onto the end of the DR3 rack assembly (Wiper Cable) that operates the micro swith had finally sucumbed after 48 years to wearing against the motor/gearbox housing, worn through and broken off, therefor nothing to operate the micro switch off = wipers on all the time!
Now just need source a cable of which I think this item on ebay may be the very thing, see the second picture for a view of the striker assy, JAGUAR ASTON MARTIN ALVIS BRISTOL ROLLS ROYCE LUCAS DR3 WIPER RACK NEW | eBay

 

good job!! you could also check with SNG Barrat, they have online parts illustrations from the original Parts Manuals which might help you pinpoint the correct rack.

should be an easy repair. Those rack systems were used until the end of 1992 in all Jaguar models up to the last Series 3 XJ-6 and XJ-12, though the motors are different.

 

Jose, SNG do not list this in their catalogues and I had an email enquiry back stating this item is no longer available!
Steve Hunt of the Ebay listing in my previous posting above has been very helpful and is supplying a new Wiper Rack, Thanks Steve.

 

Jose, Even Martin Robeys couldn't help.Hi Neil, Thankyou for your e-mail dated 27 aug 2015,i’m sorry we cannot help with your wiper rack request,good luck with your search. Regards, I *****, Martin Robey Sales Ltd

 

well at least you found a replacement.

Grease it well before inserting it back, and you need to remove the wipers first, if you don't you'll find out why !!

 

Jose, I removed wiper rack (cable) from the wiper drive box as I stated above. I folded over strands of 0.040 lock wire four times, threaded it through the eye of the wiper rack fitting and locked them into the jaws of a battery drill chuck, and rotating the cable very slowly it can be “unwound” from both wiper drive boxes and withdrawn from the wiper rack sleeving with no further dismantling. Using plenty of Lithium grease I wound the new wiper rack all the way in and it engaged with both wiper boxes first time no problems. I think clockwise wound the cable out and anti clockwise wound the new wiper rack back in but you can see this in the spiralling of the wiper rack or trial and error.
I then removed both wiper blades and re-assembled the operating arm and wiper rack inside the wiper motor gearbox (Lots of new Lithium grease) and re-mounted the wiper motor and connected the wiring.
Turn on the Wipers and allow the system to operate for four or five seconds and place the switch into park.
Wind the Park switch adjuster (the knurled knob above where the wiper rack enters the wiper motor assembly) fully anti clockwise.
Turned on the wipers for two cycles and allow them to park.
Attach both wiper blades back onto the wiper box spigots in the parked position.
With the windscreen continuously wetted turn on the wipers to the slow position, stroke adjustment can be made turning in the park knob knurled nut, this gave me overstroke so be careful to protect the paint work, when the desired stroke length is reached place the switch in park.
I then removed the wipers from their spigots again and reset them to the parked wiper position.
Checked the wiper stroke, cleaned up and went for a beer job well done.

 

excellent!

yes, the little knob is used to adjust where the wipers park.

I have removed the cable in the past in both my cars to grease them, that's why I remove the wipers because the "gear boxes" will turn as you insert the cable.

if you end up with any "skipping", it is usually the 2 nuts on the gearbox covers that are lose, and that means removing the dash cap to get to them.