'83 944 windscreen washer conundrum

[George_Mayson]

Morning all,

I'm hoping that somebody might have the answer to a problem with my windscreen washer which is causing me some grief.

Problem:- When operating the windscreen wash, the wipers work but the pump only works intermittently. It used to work ~50% of the time, now more like ~5% or less.

What I've done so far:-
New pump
New spade connectors on the lead wires
Checked earth wire - OK
Checked switch - OK
Checked getting 12V at the pump when switch pulled - OK


Here's the really weird thing though, when I attach a multi meter to the pump feed/earth wires, I ALWAYS get 12V. I've stood and repeatedly pulled the wash lever about 50 times over and I always get 12V, yet when I plug the pump back in I rarely get any action.

I have also checked the earth as best I can, when I plug a multi meter into the earth wire and touch the other lead to the inlet manifold, I get 0 Ohms resistance, hence making me think the earth is OK.
-UPDATE- Made up a new earth wire with spade connector, plugged into the pump and fixed the other end to the manifold. Still not fixed, hence problem not with the earth wire.

I have checked the new motor to make sure it's not faulty - when I plug it into another car it works perfectly 100% of the time.

As far as I am aware the washer pump is not connected via any relays or even fuses (According to the fuse/relay layout diagram in the manual).


I am convinced that this is some problem with poor connection somewhere, but the wires for the pump go straight back into the loom and I have no idea where they come out and where they are grounded to.

Is there something I'm missing? Is there a relay or fuse involved somewhere I don't know about?

Any thoughts at all on the matter would be deeply appreciated!


Best,
George

 

[albert911tg]

HI George, I presume that when you operate the switch you can't hear the pump running? If the pump is running but no water reaching the screen, check the tubing-the non-return valves & 'T' pieces fail after time meaning the block the flow. Worth a look
Regards
Albert Walsh
Register Director PCGB

 

[George_Mayson]

Hi Albert,

Thanks for your reply.

The pump is definitely not running. On the odd occasion it does run I get good spray onto the screen, so unfortunately it's not a simple tubing problem

Even when I do get the pump to run, it often cuts out again while I've still got the switch held back.

I'm trying all of this with the engine off but ignition on, so I can easily hear when the pump is/isn't running.


Cheers,
George

 

[Dan944t]

Hi George,

it could also be your stalk connection? If possible spray some electrical connection spray on the joint or at worst buy a second hand stalk but it’s just another posability which I had similar problem in my non turbo 944 many years ago and changing the stalk out fixed my problem and that was after changing the pump and the return valves and jets first.

seems like It’s a connection which is intermittent to me but just something you could try ??

good luck
atb
daniel

 

[George_Mayson]

Daniel,

Thanks for the suggestion! I'm going to try it before getting an auto electrician to look at it.

Cheers,
George

 

[zcacogp]

Tricky one. Everyone knows that automotive electrics only work when they want to and it sounds like yours don't want to.

My only thought is whether there is some break somewhere in the wire to the pump such that when you hold the wire in an abnormal position to connect to the multimeter then it works, but when the wire is connected to the pump then the break in it means no current. Can you connect the multimeter to the pump terminals when it is all in situ to see what happens then?


Oli.

 

[vitesse]

Personally,I would suspect the switch unit -it's a fussy collection of bendy things & contacts with sliding contact switch thrown in with anything being slightly out of alignment likely to lead to unusual symptoms.
Its also easy for the slip on connectors at the rear to work their way off slightly leading to bad contacts.

I'd take it off,handle very carefully too.Split the direction indicator stalk from the the rest of it carefully check all the copper/brass contacts especially the long one for straightness/alignment,clean them ,switch cleaner spray is good followed by small dabs of Vaseline & re-assemble carefully.
Refit & try before refitting the steering wheel.
I would run the engine to ensure a healthy power supply for the pump.