2 Speed Wiper Motor

[NevSpit]

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?

 

Thanks,

 

Paul.

[Pete Lewis]

just like that   !!!!

 

dont know if these will have parts for your motor but have a fair selection  of repair parts           http://www.s-v-c.co.uk/category/wiper-systems-and-parts/

[steveweblin]

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/

 

[Gary Flinn]

I believe the later motors are different, here's another Diagram from the internet?

 

[NevSpit]

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.