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Wash/wipe wiring advice please


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My windscreen wash function stopped working. Then started again. Then stopped.

So I checked the motor with direct current through two new wires off a spare battery and it worked first time, every time. So I ruled out a motor problem.

I fitted a new steering column wiper stalk and initially it did not work, then started to work and seemed fine. But its stopped working again this week. I rechecked motor today, its still working fine.

So I'm guessing I have a wiring problem somewhere between stalk and motor. However the wiring sheath with the washer/motor wiring vanishes behind the outer wing, inside the wheel arch and it is unreachable unless I start dismantling the wheel arch which I'd rather avoid.

So I've had a look at the stalk and wiring set up and it appears that the two wires that do the business to initiate the wash function are the dark green and light green going into the multiplug connector behind the steering column. When I put my multimeter on those two I can get it to beep as it makes a circuit.

My assumption is that if I cut those two wires just before the block connector on the stalk side and connect in a couple of new pieces of wire running direct to the motor I'll have it back to normal.  I'm assuming the fused power feed for wipers and wash function comes into the stalk on one of the other wires and the circuit is made there, and there's no other power feed coming into the line anywhere south of it.

Am I  correct or am I missing something obvious here?

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I don't know what vehicle yours is but on the Td5 there a light green/black which feeds the washer pump directly from the switch, also connected to a feed from the wiper delay relay, then from the pump, there is a black earth wire connected via one of the headers.

My guess from the way you describe the intermittent nature is the earth may have a bad connection, it's pretty unlikely that a wire in the harness would just break.

 

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Its a1989 110 (was 19J now 200tdi). No fancy TD5 gubbins! It has been very reliable - but I recently got in about the front end to weld in two new footwells, and a repair panel across the lower windscreen area of bulkhead, which necessitated pulling out the heater and associated bits and although I took my time and was careful its possible that something has got 'strained' whilst that was happening.

The vehicle had a 'renovation' and bulkhead replacement done by Liveridge 15 years ago and I'm still finding wiring anomalies caused by their 'cut and crimp' approach to the front wiring loom so its possible there's something in there thats 'fragile' as a consequence of their less than careful workmanship.

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9 minutes ago, Jocklandjohn said:

Its a1989 110 (was 19J now 200tdi). No fancy TD5 gubbins! It has been very reliable - but I recently got in about the front end to weld in two new footwells, and a repair panel across the lower windscreen area of bulkhead, which necessitated pulling out the heater and associated bits and although I took my time and was careful its possible that something has got 'strained' whilst that was happening.

The vehicle had a 'renovation' and bulkhead replacement done by Liveridge 15 years ago and I'm still finding wiring anomalies caused by their 'cut and crimp' approach to the front wiring loom so its possible there's something in there thats 'fragile' as a consequence of their less than careful workmanship.

Pop the end cap of the left stalk off & make sure the copper strips are clean, don't loose the spring, the 2 copper fingers can be touched together to get the motor to run, my 110 is a 1989 vehicle too. 

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Just now, western said:

Pop the end cap of the left stalk off & make sure the copper strips are clean, don't loose the spring, the 2 copper fingers can be touched together to get the motor to run, my 110 is a 1989 vehicle too. 

Hi Ralph - I've got a new stalk on it - only a month old to replace the other one so pretty sure its not the culprit  (I couold be wrong!) but tomorrow if the sleet stops I'll pull it apart and have a look.

 

5 minutes ago, crwoody said:

Ah right, often more than meets the eye when there's "history".

Just a case of plod on through then, having said that, there should be no issue with wiring direct and isolating the original wires as you've suggested.

If the stalk (as above) proves ok I'll splice in two new wires!

 

 

Thanks chaps.

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Ok - not as straightforward as I thought!

Running two wires from the stalk to motor wont work, the washer pump wont run (although the wipers themselves will work) I'm assuming because there's a relay somewhere in the original loom. Is this correct, and if so where is it - in behind the metal fuse box?

 

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12v to light green /black wire at the pump end, should make washer pump run. Normally no relay for pump (but wiring could have been modified, to only wash when wiping 😮), but take the supply from the battery via a fuse, for testing, not the stalk as there is a relay in the supply to the stalk. Or use the plain green wire at the stalk which should be a 12v live switched from the ignition and connect to LGB wire.

Edited by simonb
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Thanks Simon. Its got a wee bit clearer (sort of!).

Today with the meter I got 12v at the pump end of the wiring when I push the stalk to wash as would be normal. Also got the pump to run normally with a pos and neg attached off a spare battery.

But when I connect the original wiring to the pump it wont run. So I thought 'earth' and piggybacked a wire off the neg on the pump to the chassis and hey presto it runs. I can push the stalk and it squirts just dandy.

So its an earth problem.

But lights and everything is all working ok....except aux spotlights and some pressure/temp/oil guages and some other bits.....

So I started looking more closely and realised that the auxiliary equipment I have running in the van off a new fuse board I fitted is ALL not working because the ignition-switched relay is not energising. The fuse board has two sides, one permanently 'live' and the other ignition dependent. I connected a crocodile-clipped wire between the relay and the permanently live side of the board and the relay pinged, and all aux equipment came on.

SO whatever earth has failed its connected to the relay energising wire which I've taken from behind the dash, and if memory serves me correctly I used the feed for the rear wash/wipe which I didn't ever use and removed, so tomorrow I'll follw the relay energiser wire into the dash and see whats afoot.

 

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1 hour ago, simonb said:

12v to light green /black wire at the pump end, should make washer pump run. Normally no relay for pump (but wiring could have been modified, to only wash when wiping 😮), but take the supply from the battery via a fuse, for testing, not the stalk as there is a relay in the supply to the stalk. Or use the plain green wire at the stalk which should be a 12v live switched from the ignition and connect to LGB wire.

Simon - where the relay in the supply to the stalk - is it tucked down the back of the metal fuse holder on the bulkhead above the tunnel?

 

Edited by Jocklandjohn
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1 minute ago, western said:

Nearly cured then, that's good detective work. 

Getting there!  Weird behaviour on the metal  fuse panel on the inside though - when I put the meter pos and neg one on each end of any fuse I get no meter response (and the same behaviour if I do the same on the other side strip of fuses). However if I put one probe on the outer (left) side on the left line of fuses, and the other probe on the right side of the right-hand fuses strip the meter reads 14+V (engine running) so it looks like some earth problem. Will loosen and clean the chassis earths tomorrow.

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2 minutes ago, western said:

the wiper motor has it's own earth to body as well,  there should be a plain black wire from the body to the retaining clamp fixing screw. 

Ah - I remeber seeing that - I'm pretty sure I cleaned it and refixed but worth checking, Are there any other local earths in the central dash area?

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Well I removed the earth straps from gearbox and batteries to chassis and gave a good scrub, also the small bulkhead one beside the steeering column. Appears to have made no difference.

I messed about with the multimeter and I have to say the internal shenanigans has got me stumped.

Here are some of the anomalies:

The windscreen wash motor, which started all this, apparently wont work because its lost its earth. Earthing the pump locally at the front inner wing will allow it to work. So far so good. I could do that but....

The Auxiliary Fuse Board I installed with several items running off it is switched through an ignition-dependent relay (using an ignition fed supply from the now redundant rear window wash power wire) and its now NOT switching on. Also, a pair of relays triggering other items, both of which were also using that rear wash/wipe power feed are not working either. Reconnecting ALL of them to a new 12V supply WILL get them to function.

So that points to some problem with the rear wash wipe power supply or its earth.

But its behaving oddly. Its the ONLY fuse in the bulkhead fuse holder that shows 12V across it! Despite not energising any of the attached relays as mentioned above, it shows 12V when the meter is across the fuse. However with the meter across any of the other fuses in the two strips there's no 12v (although all the individual stuff is working ok). BUT if I meter across two separate fuses - one from the left fuse strip and one from the right fuse strip I CAN get 12V.

If I remove a fuse (eg I tried this with the indicators - pulled both L and R side the fuses out) -  the indicators still work. That seems really weird?

As far as I can recall when I started trying to track down the washer issue ALL the other auxiliary stuff thats ignition-relay-triggered on my additional fuse board was working fine (although I could be wrong).

Only thing Ilve done I can think of is when I decided to run two new wires through the dash to replace the wash motor wires I poked a very thin plastic rod through to fish the wires back with. Is it possible I've pulled something off in the dash wiring behind the steering wheel thats created this issue?  Is there any specifc wires in the main loom that are in there that mght cause this if easily diconnected/broken?

Any suggestions whats going on with the fuse holders that they only show 12V across 2 fuses and not one? Thats got me baffled.

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