Talk Morgan Forums Morgan Sports Cars Maintenance & Servicing Windscreen wipers don't switch off

During a recent trip the windscreen wipers were just twitching when switched on, investigation revealed that the nut which secures the drive cable to the motor assembly had come undone.

After securing the nut, and this may be coincidental, the wipers don't stop when the switch is turned to off, eventually they stop of their own accord but this can be up to 5 minutes after selecting off. Any suggestions?

Thanks

Perhaps the circuit breaker in the wiper motor isn't working properly. Mine looks like this one (exploded view): http://www.s-v-c.co.uk/wiper-systems/ Perhaps your is similar.
If you remove the gear box cover of the wiper motor you will find a gear wheel which moves the 'connecting rod' (between the gear and the cable). The gear wheel has a 'cam' on the underside which operates the switch that cuts the circuit when 'off' is selected. If the cam is worn or the gear wheel has come close the cam will not 'reach' the circuit breaker.

/Thomas

Have investigated further, if I slightly slacken the nut which secures the drive cable into the motor body the wipers work correctly, if I tighten it up just using my fingers it malfunctions. If I leave it slack the nut will undo again and the drive shaft detaches - so much for hand-built cars!

Any suggestions on a permanent solution.

Cheers

It seems that tightening the nut is creating some tension in the rack which is interfering with the self park. This may not be easy to resolve, but I would start by removing the wiper arms. Then connecting the nut properly. See if it works properly with no arms to move. The arm position could in theory interfere with the self park.

If it doesn't work with no arms, then you need to look inside the motor to work out what's happening.
The alternative is to fit a shallow locknut between the motor and the rack, but this would only address the symptoms, not the cause.

http://www.theminiforum.co.uk/forums/topic/263094-wiper-motor-testing-fault-finding/

Page 42 here on GoMog:
http://www.gomog.com/allmorgan/LucasFault.pdf

http://club.triumph.org.uk/cgi-bin/forum10/Blah.pl?v-print/m-1237670018/