General No Wipers - Help!

[Stilo Stew]

Hi All.

My windscreen wipers (front and back) have decided to stop working at the same time, not much fun with all this rain around!
Have checked the fuses (F43 and F52) and also replaced a relay (T12).
The bloody things still won't work!
Have disconnected each wiper motor in turn to rule out a short and checked all other obvious connections. I'm fast running out of ideas!
Anybody experienced this fault before? If so your input would be much appreciated.
(Car is booked into Uncle Arnolds next Tuesday for a checkup otherwise!)

Cheers.

 

[Deckchair5]

Use a multimeter or circuit tester light and check where the power stops. You have the right fuse and relay but is power actually goiing through.
Does nothing else on the wiper stalk work like washers etc?
The front and rear wiper motors have different earths of course so it won't be a bad earth from the motor.

The relay T12 needs an earth though supplied at earth point C15. Does the relay click if you pull it out and re insert it with ignition on?




I'd check power on either side of the fuse, power out from the relay and power into the wiper switch connections. If you have power in to the wiper switch on Pin 11 then check for power out of the switch

 

[Stilo Stew]

Cheers for that Deckchair.
I'm on holiday just now but will go in to work and get a DMM tomorrow and check the whole thing out, good schematics, just what I was needing!
BTW - Does anyone know if Haynes do a Stilo manual yet?

 

[Deckchair5]

Nah Haynes don't do much with cars these days, too complicated for them. Haynes recent manuals seem to be diversifying into new markets
http://www.haynes.co.uk/webapp/wcs/...10001&storeId=10001&productId=17801&langId=-1

 

[ChrisMClark]

I emailed Haynes and they said that they had no intention of producing a manual for the Stilo as it's not that popular (or words to that effect). So I replied stating that much of their info in other manuals I'd used was actually rather misleading, badly worded, and also asked if they'd discovered colour photography and printing yet :devil: I'm such a bitch!

 

[Stilo Stew]

Hi All.

Ah, Haynes - no longer the mecca of amateur motor mechanics!
Never mind, there are always you guys to help us less informed!
Back to the wipers.
Started the car earlier and thought 'I'll try the front wipers'.
Guess what, the bloody things sprung into life!
Here's the catch, they only went on constant slow speed and wouldn't switch off!
Only stopped when I switched the ignition off.
Tried again but back to nothingness!
This is getting stranger by the day!
Think I'll have to leave it to a serious car electrics mechanic (=lots of money).
Will update you all when it is fixed.

 

[Deckchair5]

Sounds like the wiper switch. Have you checked the connectors at the switch?

 

[Stilo Stew]

Hi All.

A quick update.

Have been into the steering wheel column to check the wiper stalk connector.
Nothing obvious there. Have checked the stalk connector - was clean and tight.
The more I look into this problem the more I am convinced that it is a fault related to the wiper motors alone as all other controls (washers, trip computer) are working fine. I've tried disconnecting each motor in turn to rule out a motor fault but it has not resolved the problem. The fact that the washer pump is still working makes things weirder as the pump shares the same fuse and relay as the wipers.
Question - Does anyone know if there is a secondary fuse between the relay and the wiper motors? If so, it would explain the problem. If there is no fuse then I am seriously scratching my head!:bang:

 

[Deckchair5]

Ok Don't panic. Just be logical and systematic
You know you have power into the switch. There are no fuses downstream form the switch to the motors so you just need to check power supplies from the switch and earths

Here's a piccy of the rear wiper circuit- this is different from the one above which shows the front wipers and washers

N16 is the rear wiper N22 is the washer for front and back
Note the washer feed and return is supplied by the switch, it doesn't have its own earth like the wiper motors as the same washer motor does the front and the back screens. The switch decides which direction the pump turns and that decides where the water goes. That's why the washers will work but not the wiper motors

But the wiper motors need earths and they each have their own. You could have a coincidence of both motors losing their earths (bit far fetched) or power supply isn't coming from the switch (more likely)

Back to the wiper switch
Check for power out at pin C3 (shown as H= grey but diag could be wrong) with rear wiper selected. If you have power out then you know power is going to the rear wiper motor.
If it is then dive into the tail gate and check at the rear wiper motor itself for power and a good earth. If the motor has power and earth then it's gotta go or it's seized/ broken (not likely on Stilo)

Similarly trace the power and earths for the front wipers

 

[Stilo Stew]

Cheers for going to all the trouble there Deckchair!
I'll definately have another look when I get hold of a DMM to check that there is 12V going to the wiper motor when the wipers are switched on. If there isn't, where does the supply come from, another module further down the line?

 

[Deckchair5]

The supply for the rear wiper comes out of the switch then into the body computer then it's straight from the body computer to the rear wiper motor. So check for any power out of the wiper switch on pins c3 and c4 -one's intermittent wipe and one contiuous

Then check for power at the wiper motor and check the wiper motor earth has zero resistance to a good earth on the body
I would check the connectors G and D at the body computer too as the wiper wiring goes through them

 

[Stilo Stew]

Cheers Deckchair, a few things to check out there!
Might be able to get hold of a DMM over the weekend so will update if I find anything.

 

[Stilo Stew]

Right then!

My wipers have sprung back to life!
I don't quite know if this was a coincidence or not, but I had the aircon on for a while (yes, it gets warm in Scotland!) this afternoon and ran into a short, sharp shower. Switched on the wipers without thinking and hey presto!, I had intermittent wipers. Tried all settings front and back and everything worked!! Have been working fine ever since!
So, I can't take the car to A/C's on Tuesday as I have no fault to diagnose!
Never mind, money saved towards my road tax.
Deckchair, a personal thank you for all your pointers and assistance.:worship:

 

[Deckchair5]

Excellent. Amazing how moving a few connectors can make the magic work again. Will it hold up though?
I'd give all the connectors you can get to in the wiper circuit a disconnect and clean out. Try to get to the body computer ones if you can