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2 Speed Wiper Motor


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Hi all.


Finally got around to investigating why my windscreen wipers only worked on high speed and did not self park.


I have dismantled the motor and when I removed the brush plate the springs / wires on the brushes were rather corroded, so much so that one of the opposing pair just disintegrated. After some searching on the web I found that this is the slow speed brush so that would make sense why it wasn't working!  I hope to go to the NEC at the end of the month so a replacement will be on the shopping list.


However, I was then trying to work out how the two different speeds work and my brain is failing to grasp it.  It appears that the high speed brush is a different shape but still touches the commutator in the same place although it is at a different angle i.e. not opposite the remaining brush. So how do the two speeds work then?


Can anyone enlighten me?





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Triumph used Lucas 2 speed wiper motors. To get the change in speed the switching circuit includes an electrical resistor. Switching the resistor out of the circuit means a higher current can run the motor faster.

Here is a circuit diagram borrowed from a Danish Triumph enthusiast: http://www.thorden.dk/



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  • 3 weeks later...

Thanks all, my motor is wired as per Gary's diagram.  


I took the time to dismantle everything and give it a good clean including the parking switch (it certainly needed it) and picked up a new brush set from SVC at the NEC show. Taking some inspiration from Bordfunker I also rubbed down the bulkhead around the motor and resprayed it. End result is that I now have the luxury of two speeds and self parking  - wahhey!


It appears that the two speeds on these models are just down to the positioning of the brushes.


Wiper Motor


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