Wipers slow and wash wipe not working

DLN1965

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Sep 8, 2020
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43
Morning all
Have a little issue
Wipers only work on fast (and don’t park either). Jets work fine
I tried fuses, control relay, switch, wiring even changed the wiper motor ….. all to no avail !
It only works on fast speed …..

I know ‘fast’ speed is fed to the wipers separately…. So that works ok
Any ideas if I’ve missed anything OR something obvious I didn’t check
THANKYOU
 

Duncodin

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Pontrhydyrun - in Crow Valley
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M44 FrankenZed
The fast speed is a direct power connection while the slow speed goes through a resistor pack. Now I must confess that I don't know if the resistor pack is built in to the motor assembly if it's a separate thing.

I tried looking at the wiring diagram and can't see any resistor pack as a separate thing so it's like in the motor assembly

You said you changed the motor. For a new one? Or was it off ebay - maybe somebody had the same problem and their duff one is doing the rounds.

Also the switch could be faulty. Relays, fuses.
 

BinJuice

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British Zeds
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Mar 31, 2019
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East Devon
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Z3 2.2 Sport
Had this happen on mine when I first got it, turned out to be the "wiper control module" located under the glove box. Mine was white with green writing on it
Available on the bay at about £12 used.
Sorry dont have car anymore to give part numbers.

Keith
 

DLN1965

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Sep 8, 2020
Points
43
The fast speed is a direct power connection while the slow speed goes through a resistor pack. Now I must confess that I don't know if the resistor pack is built in to the motor assembly if it's a separate thing.

I tried looking at the wiring diagram and can't see any resistor pack as a separate thing so it's like in the motor assembly

You said you changed the motor. For a new one? Or was it off ebay - maybe somebody had the same problem and their duff one is doing the rounds.

Also the switch could be faulty. Relays, fuses.
Will try again with another module, and fuses
Will test incoming and outgoing from the switch
Thanks everyone
 

NZ00Z3

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Timaru, New Zealand
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3.0L, 2.8L, 2.0L Z3 Roadsters
There is a vehicle speed input into the wiper module. This means that the wipers will only work on intermittent when on the slow speed switch with the car stationary.
 

DLN1965

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Points
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There is a vehicle speed input into the wiper module. This means that the wipers will only work on intermittent when on the slow speed switch with the car stationary.
I knew about this bit …..
BUT. It doesn’t work on any speed, barring fast, even when in motion
And the intermittent / sweep when jets are on don’t work either
 

Duncodin

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Having scratched my head a bit more I've.come to the conclusion that theres no resistor pack at all. The motor is a two speed motor with different windings for slow and fast.

But intermittent and park are controlled by the wiper control module. You said park doesn't work.

I'd be looking for the control module behind the glove box.
 

DLN1965

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Having scratched my head a bit more I've.come to the conclusion that theres no resistor pack at all. The motor is a two speed motor with different windings for slow and fast.

But intermittent and park are controlled by the wiper control module. You said park doesn't work.

I'd be looking for the control module behind the glove box.
so ….. in theory at least slow and fast should work and intermittent and park not ?

the only speed that works is fast …. With no slow / intermittent / park (have to turn them off with good judgement, at the bottom of the stroke)

possibly my bad luck buying an one from an auction site which didn’t work ??

Will try again!!
would be good if I could test with a known working one ….. similarly with switch
 

Duncodin

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I think fhe wires from fhe switch go to to control module which controls the relays. So, in my mind, it's the control module that sends the power to the motor. the first thing I'd look at is that control module.
 

DLN1965

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I think fhe wires from fhe switch go to to control module which controls the relays. So, in my mind, it's the control module that sends the power to the motor. the first thing I'd look at is that control module.
Unless ….. I have no power …..at the switch for the slow/intermittent/park selection??
 

Duncodin

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Unless ….. I have no power …..at the switch for the slow/intermittent/park selection??
You can check the outputs from the switch with your multimeter.

I suppose, now that I've said that, you can check the wires into the motor to see if the correct wires are live when expected.
 

DLN1965

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Swapped wiper control ….. and it’s the same !

so going back to the switch !!
Will have to get my tester out and see which live isn’t (if you know what I mean?)
 
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