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-   -   Windscreen wipers gone berserk! MOT fail, HELP!! (https://www.the75andztclub.co.uk/forum/showthread.php?t=316638)

MartinBrighton 30th November 2021 18:30

Windscreen wipers gone berserk! MOT fail, HELP!!
 
Hi there, I'm new to this forum and have an issue with my car's front wipers. They go berserk and then stop at any point in the screen, thus MOT failure. The wipers do this no matter which position I choose on the stalk.
They are auto wipers. I have read about the plenum drains and these are clear. There is no water in the boot either.
Can someone advise which fuse to check and where it is? And whether the wiper motor is fitted with an auto park function? If so do I need a new wiper motor?
I am no mechanic and any ideas shall be greatly received, cheers, Martin

Retap 1st December 2021 14:01

Hi.


Somebody with knowledge better than mine on wiper problems will turn up eventually with suggestions better than mine but i can tell you the in cabin fuses are located beneath the glove box and some more fuses can be found in the engine bay next to the battery but these engine bay fuses are more main bus supply than equipment fuses i think. In all honesty i cant see this been a blow fuse problem but you never know... Sounds more like faulty electrical connection somewhere, faulty motor/sensor or even bad wiper linkage.

For the in cabin fuses look Under the passenger footwell below the glovebox at the front bottom there are two screws with slots in big enough for a small coin, once undone the flap drops down and the fuse index is printed handily on the back of this flap in a way which requires a broken neck to read so take ya phone its easier than broken neck to reference that way. Also note there are differences in the fuse layout depending on car year so use your fuse index.


With the wiper going mad and being eratic i would be looking first if its a constant speed on any setting or does it respect the control stork speed? also hows the mechanical wiper drive arm "linkage", looking at the linkage and motor that can be found under bonnet driver side possibly need to lift the leaf cover up that hides the brake fluid reservoir as thats also where the wiper motor is and its afore mentioned drive arm linkage. Under there are also electrical connectors for the motor, are they looking dry?





EDIT


I advise you split the problem in half by looking at it from two ways to eliminate one side thus moving closer to the cause, is the motor being driven correctly i.e is the motor receiving power at the right times and depending on that finding is the motor faulty? Choose which is easier to answer.... Got a spare wiper motor? Got any other strange electrical faults? Just checked ebay and you can snap up a used motor and linkage dirt cheap if diagnosis skills are limited.

Retap 1st December 2021 14:42

Quote:

Originally Posted by MartinBrighton (Post 2910388)
Hi there, I'm new to this forum and have an issue with my car's front wipers. They go berserk and then stop at any point in the screen, thus MOT failure. The wipers do this no matter which position I choose on the stalk.
They are auto wipers. I have read about the plenum drains and these are clear. There is no water in the boot either.
Can someone advise which fuse to check and where it is? And whether the wiper motor is fitted with an auto park function? If so do I need a new wiper motor?
I am no mechanic and any ideas shall be greatly received, cheers, Martin




Theres some interesting clues in this thread..


https://www.the75andztclub.co.uk/for...ghlight=wipers




and for £12 delivered used motor and linkage on ebay, might help rule out the mechanical side being the culrpit but then again you could end up buying the shed spiders a new climbing frame.


https://www.ebay.co.uk/itm/263781349...QAAOSwnDJbMrb4

SD1too 2nd December 2021 09:23

Quote:

Originally Posted by MartinBrighton (Post 2910388)
They go berserk and then stop at any point in the screen ... The wipers do this no matter which position I choose on the stalk.

Hello Martin,

The first thing I would check is the security of the wiper stalk electrical connector. Has any work been done recently in this area which might have disturbed it?

I acknowledge that you're not mechanically minded but, as Retap has said, release the leaf guard on the driver's side (black plastic lattice with two clips at the front) and you will see the wiper motor's electrical connector. Brush away any debris then pull out the plug and reinsert it.
Quote:

Originally Posted by MartinBrighton (Post 2910388)
Can someone advise which fuse to check and where it is? And whether the wiper motor is fitted with an auto park function? If so do I need a new wiper motor?

It's not going to be a fuse Martin. Fuses cut off the power supply in the event of a short circuit in which case the wipers wouldn't work at all. Yes the wiper motor has an auto park function. If that had failed you would expect the wipers to keep going and never park. It's impossible to say whether you need a new wiper motor but I doubt it. I've never heard of one giving trouble.

Could the garage which did your MOT test look at it? Alternatively try to find an auto electrician. There's also a business in Brighton specialising in the 75/ZT but I can't remember it's name!

Simon

COLVERT 3rd December 2021 12:29

I think the motor function is enabled by being earthed.--Maybe the earth wire is frayed and shorting down to earth when it shouldn't.---:shocked:

Dolomite 4th December 2021 16:04

The wipers get there power through two relays in the under bonnet fuse box, one relay does the on off and the other does the single and double speed, the relay gets its signal from the module, if you know how to use a meter you can see whether the relay has failed or whether it’s being told to switch on. The relays are identical so you can swap them an see if there is any change

MartinBrighton 4th December 2021 16:34

Windscreen Wipers going berserk
 
Hi there, many thanks to those who took the time to try to help with my wiper malfunction problem.
My mate had a look at the relays that control the wipers. As soon as either of the 2 relays controlling the wipers was taken out then the wipers immediately stopped. So in his view it is not the relays that are causing the problem.
One thing that I failed to mention in the original post is that the wipers continue to work even once key is taken out of the ignition.
As previously stated, the wipers go for 14/15 sweeps of the screen no matter which position the wiper stalk is placed in, and stop wherever they choose on the screen, thus the MOT failure.
There are seemingly no other electrical issues, alarm etc..,
Is it as simple as a new wiper motor? My mechanic mate isn't so sure of this because the wipers continue after keys out of ignition.
Any further advice gratefully received, Martin

suzublu 4th December 2021 18:56

Fitted a new radio by any chance?


Sent from my SM-A326B using Tapatalk

COLVERT 4th December 2021 22:30

It's not the motor. It's doing what it's told to do.


It doesn't matter that the ignition is off. Once the ECU supplies power to the motor that supply is continuous until the movement of the arm disconnects the earth to it.---:trans:

slovcan 5th December 2021 04:39

Quote:

Originally Posted by COLVERT (Post 2910863)
It's not the motor. It's doing what it's told to do.


It doesn't matter that the ignition is off. Once the ECU supplies power to the motor that supply is continuous until the movement of the arm disconnects the earth to it.---:trans:

Hmmm, just a thought. The OP said it happens when the wipers are set to automatic. Maybe unplug the rain sensor up behind the mirror to see if that exorcises the demons.


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