Windscreen Wipers Failed!

[PersonaNonGrata]

My windscreen wipers failed today on my way to work this morning. One minute they were completely OK then the next minute they refused to work at all.

The wipers themselves parked themselves properly at the bottom of the screen but refused to move at all after that – they had been on as a result of squirting the windscreen with windscreen wash.

Now they have failed before, but have always started again. They always fail in the parked position.

Now I’ve got a journey home with low visibility to worry about.

Help!

[AndyPandy]

If the fuse is intact,then it sounds like the motor,and/ or switching mechanism is at fault

( switch which changes motor direction ,at the end of its stroke) . Try tapping the motor

with a small hammer ,(Whilst it is switched on)as it might be the brushes inside the motor

sticking ,or worn down ,and not fully connecting with the motor commutator ( motor shaft revolving

electrical connections) . If you get it running by doing this ,then a new motor is needed.

Of course it could be the stork switch at fault.

Edited 12 February, 2010 by AndyPandy

[ap0gee1978]

Can't say for sure on your car, but issues with either not shutting the bonnet properly or a fault with the bonnet switch itself will prevent the wipers working. Got to be worth a try...

[Yes_Dear]

I had exactly the same problem on mine. - they kept stopping in the park position randomly for a few hours then started working again.

I replaced the wiper relay (the big brown one in the drivers footwell) about 6 months ago and haven't had any problems since

[PersonaNonGrata]

Can't say for sure on your car, but issues with either not shutting the bonnet properly or a fault with the bonnet switch itself will prevent the wipers working. Got to be worth a try...

Thats interesting - the wipers work even when the bonnet is wide open.

Maybe it is this switch as you suggest. The switch itself is showing closed circuit when the bonnet is open - just need to check out what it should be.

If that doesn't work then the relay will be next for replacement. I will also grease up the mechanism today as I have some time on my hands.

Thanks to all for the replies people!

[PersonaNonGrata]

Update:

I tried setting the windscreen wipers going with the bonnet switch closed, and with the switch open (I just unplugged the switch so that the car would see an open circuit). In both cases the wipers ran just fine. So, on this car at least, the bonnet switch doesn't seem to make any difference. So thats a bit odd.

Then it was a case of pulling out the mechanism and greasing up the pivots. When on the workbench it seemed to me that the mechanism was pretty free and wasn't seizing at all. I greased every joint anyway and replaced it. Whilst in that area it seemed sensible to replace the pollen filter - so that was replaced too.

Looking at the mechanism in place and running, the motor runs in one direction only and relies on the mech layout to give the 'back and forward' movement of the wiper arms, so there must be a switch inside the motor that is looking for the 'parked' position. I'm guessing that the car uses a latching relay for the wipers and the 'parked position' switch breaks that latch - when the demand has been removed (i.e. driver has switched the wipers off using the stalk switch).

Since my wipers always fail in the parked position its likely that the switch in the motor is OK. The other bit of evidence for this is that the wipers always stop when I've turned them off, and work fine in intermittent (when they were working in the first place that is!).

I guess that means that front wipers that don't turn themselves off when they are supposed to MUST have a dodgy switch in the motor (or bad connection from the switch)

At the end of all this the only things left are the relay and the stalk switch. The stalk switch has five positions that will switch the wipers on, and none of them work when the wipers are playing up. Surely all five switches can't fail at once!

Must be the relay. It just must be!

[guzzigeezer]

Two electromagnetic changeover coils control the wipers voltage supply, and are switched on and off by a microrocessor in the wiper control module. Clean off the relay contacts in the control unit Marked 377 in the footwell relay panel above pedals.

The Plastic cover just pulls off control unit. Use lighter fluid on peice of card to clean contacts or contact cleaning strips. http://cpc.farnell.com/electrolube/ccs020/electrolube-pck-20-clean-strip/dp/SACCS020 Make sure both sides of the contacts are cleaned. Check contacts not pitted or burnt. Can be filed smooth if required.

9 times out of 10 this sorts the problem and saves £40 on replacing the module

This also applies to wipers not switching off or stopping in the wrong position

[PersonaNonGrata]

Two electromagnetic changeover coils control the wipers voltage supply, and are switched on and off by a microrocessor in the wiper control module. Clean off the relay contacts in the control unit Marked 377 in the footwell relay panel above pedals.

The Plastic cover just pulls off control unit. Use lighter fluid on peice of card to clean contacts or contact cleaning strips. http://cpc.farnell.com/electrolube/ccs020/electrolube-pck-20-clean-strip/dp/SACCS020 Make sure both sides of the contacts are cleaned. Check contacts not pitted or burnt. Can be filed smooth if required.

9 times out of 10 this sorts the problem and saves £40 on replacing the module

This also applies to wipers not switching off or stopping in the wrong position

Excellent, thanks.

I've done it now, and the contacts were clean and didn't look too bad (though its hard to tell when they are so tiny). I sanded them lightly using fine wet&dry and blew them out with an airline.

Fingers crossed.!

[PersonaNonGrata]

Just to add closure to this topic.

Cleaning the contacts on the relay didn't work. Neither did replacing the relay.

I had to replace the wiper motor in the end and now they work perfectly