Windscreen washer pump problem fix

[BrianG]

I thought other owners might be interested in the cause I found for
a non-working windscreen washer pump.

Mine developed an increasing failure to run when the button was
pressed, but jiggling the button would eventually make the pump
run, that is until it finally stopped altogether - although the
wipers ALWAYS operated faultlessly.

On checking the wiring diagram, the push button on the end of the
stalk only has one contact, and this goes to the Body Processor
Module (BPM), so it should have been an ''all or nothing situation''
of washer pump and wipers. Just in case, I prised out the button
cap and cleaned the small p.c.b. inside, plus the conductive rubber
button (these can go high resistance, just like in your t.v. remote
control!) but this had no effect.

The fault was therefore either the BPM output drive to the pump,
the wiring loom or the pump itself. I took out the washer reservoir
(no mean task to get to the front two bolts!) and removed the pump.
The connector looked fine - no crud which I was perhaps expecting -
and the motor was reading about 2.2 ohms so not burnt out. I took
it indoors to check it in the sink using a small 12V battery (Don't
run these motors without water or they will quickly overheat).

Motor OK, so back to the car. I hooked the test meter up to the
connector and found it switched on 12V when the stalk button was
pressed. The meter does not impose a real load like the pump motor,
so it could have been either a bad power wire or ground connection
stopping the pump from working. Then I poked a tiny watchmakers
screwdriver up inside each contact on the connector to scrape them
clean and it came out covered in..... WAX. It seems that Jaguar
back-fill the top of the connector body around the wires with this
stuff and it gets into, or migrates with time to inside the
contacts. I cleaned as much as I could and pluged in the pump - a
few splutters - but this was progress. Lots more cleaning with IPA,
followed by WD 40 and the pump ran solidly. Now put all back
together and seems to be fine.

An altogether interesting variation on the theme of ''LUCAS, Prince
of Darkeness'' connector problems, for those who remember 70's
electrical gremlins on many British cars!

[joejag308]

Brian, great report, very useful, it will make good mag stuff if thats ok with you...........Joe

[BrianG]

Joe, yes that's fine by me. I have since been advised by a poster on the Jaglovers site (where I also posted this report) that the "wax" is actually hardened dielectric grease. He reckons it's a big problem on Volvo automatic gearbox connections apparently, so it could be that the Ford-PAG "standard part" approach in this case is not wonderfully good! (I would have thought that a quality silicone-based dielectric grease would not harden in this way).

It would seem it's not isolated to just that connector on the washer pump - I have noted it on some others, such as the air conditioning / heater electric water pump, so that's another reason the pump can stop working in addition to the usual worn out carbon brushes. This stuff could be a ticking time bomb for our cars as they age, so perhaps it deserves a wider audience.

[joejag308]

Brian many thanks for that, if you find any more out on the subject maybe it could be made into a follow up story......
I need a few postings with pictures ect as i have got to get something into the mag........its harder than i thought!!....Joe

[prospero]

My washer bottle is leaking.
It's different from Brian's (no holding down bolts),being about 2" diam,
with nothing attached to the plastic body. By that I mean no wires or tubes
entering or leaving.
The body of the bottle is set into a socket which is part of the bodywork/engine bay floor.
The bottle will fill to the brim,then leak(from somewhere) down to half full.
The motor is working,but there is not much water coming through the
windscreen nozzles.
I need to find out
1. Is the bottle a straight pull out,with the wires and
tube attached to the underside?
2. Is the pump underneath the bottle?

Any info will be appreciated.

kendel.

[geo912]

From your description I would venture you have located the filler neck, which is telescopic and does tend to leak if filled to the brim. The main tank is below the strengthening plate, not easily visible or accessible, the pump is situated at the bottom corner of the tank, access can be gained by partially removing inner wheel arch mud protector. Pump can be removed by feel rather than thought, remember to syphon the tank dry first or endure the flood ( like me ).
geo912.

[geo912]

woops, forgot to mention, my jag is X308 MY2000. no intention to mislead.
geo912

[prospero]

From your description I would venture you have located the filler neck, which is telescopic and does tend to leak if filled to the brim. The main tank is below the strengthening plate, not easily visible or accessible, the pump is situated at the bottom corner of the tank, access can be gained by partially removing inner wheel arch mud protector. Pump can be removed by feel rather than thought, remember to syphon the tank dry first or endure the flood ( like me ).
geo912.

Thanks for the interesting info.
I think I know what I'll be doing this week end.

Prospero.

[geo912]

Best of luck, careful removing pump they are expensive, I was quoted £50,00. ( totally absurd ). You may just have a partial blockage caused by sucking up crud from tank bottom..As stated in previous post don't run the pump for more than a few seconds without water flow.
geo912