Motor wiper testing.

30 Jun 2009
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United Kingdom
The fuse keeps blowing on the front wipers, even when the wipers have not been activated.
I have disconnected the motor via the linkage under bonnet, if I then install fuse, the fuse does not break, only breaks when motor is connected.
It's a Nissan Venette 2.3 diesel, 2001.
Wiper Moter is Bosch 964.
There are five terminal points mounted to motor body.
Three which lead to towards motor windings. (Green, Red, Brown) and two towards the mechanism that controls the wiper arms. (black, orange.
I have done continuity test between each point and get closed circuit readings, is the motor stuffed? Or can I safe it?
Not yet removed the fixing head that contains the rotor and stator yet.
Please advise, thank you.
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As you probably know the motor gets power all the time to allow it to self park at the bottom of the screen.
Try connecting the same colour wire to earth that the rest of the car uses (have a look at an earth point, I'm guessing brown) and power up each wire, to test.
Someone mentioned on another thread that the BMW gets grease on the electrical contacts/brushes inside, so this might be the trouble here. Can you strip the motor for a clean in prtrol?
Otherwise there is a winding gone to ground and you have whats known in the trade as a short, replacement motor needed.
There was evidence of water ingress (this was after the snow&thaw) at the plug connections. So cleaned and dried, then without motor connected, the fuse didn't break. This was what I thought could have been the intial problem. But when motor connected it pops!
I have know removed motor form vehicle and taken it semi apart.
No signs of water within the rotor or stator, nothing discoloured, rusted or burnt, the brushes look to have plenty of life yet, about 10mm still visible and full movement of springs.
Taken the head/cap off, where the speed/control regulator is (is that what's called?), this is well greased and no signs of water ingress and contacts look in good condition.

I then tried to manual rotate the mechanism (crank?) that is connected to wiper arm linked assembly.
This would not budge, even with grips on it. I presumed it may have seized up during the bad weather, I had left a little WD40 around this, in hope it will free up. But since returning to problem, I then turned the stator and the crank turns freely, although gripping the crank alone, it will not turn.
Am I barking up the right or wrong tree?
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As you probably know the motor gets power all the time to allow it to self park at the bottom of the screen.
Try connecting the same colour wire to earth that the rest of the car uses (have a look at an earth point, I'm guessing brown) and power up each wire, to test.

Could you run me through these tests!
Connect the park wire to earth, then individually connect across each other wire to live. Can this be done via the battery or through the fused link?
Nope, he said look for the earth wire (negative) and connect that to earth, the earth wire likely being the same colour as the other earth wires in the car.
Then in turn connect the other wires to positive.
Personally I'd try it from a bench power supply but if not then you still need a fuse in there just in case it goes melty.

Not 100% sure but if there is a worm drive in it then you won't be able to turn it from the mechanism side.

What resistance have you got from the motor windings?
Yes connect the connector that was attached to the brown wire to the negative pole and power up the other wires individually, via a fused link. But double check the colour at an earth point.

In the self park assembly (that's what its called) you will find an earth on the gear very close to a supply, are they touching. or even damp?

No you cant turn against a worn and wheel gear assembly. Can you power the motor directly after the self park mechanism, have you got two wires going into the motor from the gearbox?

Keep in mind it wont take much, as you know, to pop the fuse. Might even have it fixed unknown to yourself?

Is this it? Cant find one listed under Vanette
So it should take around 5A max, best bench test the motor.

I still wouldn't rule out it being a fault in the loom, it could be when you plug the motor in that you have a connection back into the loom. As above, start with bench testing to rule the motor out.
Images of motor

On the first image left-right
1) Two wires=Brown and Green
2) One wire=Orange
3) One wire=Black
4) Two wires=Red and Green and Black stripes
5) Two wires=Green and Green and Red stripes

Second image
where we have brown, red and green cables at the head of the rotor

Third Image, connector from motor top-bottom
1) Two wires=Black and Green and Black stripes
2) Two wires=Orange and Green and Red stirpes
3) One wire= Green
Looking at the commutator the negative will be the brown, low speed red, high speed green.

Looking at the connector the negative is green, low speed pos black/gn, high speed pos green/red
The other two are likely going to be something to do with the parking mechanism.
Could they be connecting up to the water well and pump?
It's a tomorrow job now, but my next thought was maybe the water pump for windscreen might be the issue.
Excuse my ignorants but never really been that in to vehicle repairs, but to buy new motor is far too expensive, a used one is about a tenth of price.
But if I can repair that's good, if not best know what's failed and not end up with two motors and still have a fault.
I doubt those wires will be to do with the pump, more likely something to do with operating the motor to the park position either directly or by a link to a controller.
If this problem happened recently, could it have been when the wiper blades were glued to the screen with ice?
I reckon there's a motor winding gone to earth here......sometimes the fuse doesn't blow in time (VAG reduced the front wiper fuse from 20A to 10A at some point - I wonder if this was why :p ) but I realise this one's a Nissan.
John :)
Water pump, no
Does the water pump not still work with the fuse out? Or does the fuse control the wipers and pump?

You will get a motor from a breaker for small money, stress free?

Car electrics are an art form

As already said, earth (negative) brown (on the first image). Red or green to positive should give you motion, but will be bypassing the auto park switch, which may well be your peoblem
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