[Nikolai]

Hi all,
My 156 wipers started moving by themselves the other day. Just one wipe but with anywhere between 2 mins and 1 second between. It might have been spitting at the time so I looked up the operation of the rain sensor and apparently it only does its thing when on intermittent, and the switch was off.

I took the wiper motor out, took the lid off (it's a 5pin motor on a 2005 JTS) and saw the contact plate was caked in grease from the worm drive so I packed it back into the motor and cleaned the plate.

Not had a chance to test it back in the car yet but has anyone had experience of this before? I'm guessing it could be the motor and its controller, the wiper ecu, or the column switch. Would be ideal to not have to buy all 3 if there's some knowledge on here about how to narrow it down!

Thanks

 

[David C]

... saw the contact plate was caked in grease from the worm drive so I packed it back into the motor and cleaned the plate.

I'm sure the rotary contact plate is supposed to have that contact grease on it...

If you run it dry it will probably wear a hole in it quite quickly. Then you will need a new motor!

 

[Nikolai]

Hmmm. This confuses me as grease is an insulator, wouldn't it break the conduction between contact and plate?

 

[ALFAPAT]

I'm sure the rotary contact plate is supposed to have that contact grease on it...

If you run it dry it will probably wear a hole in it quite quickly. Then you will need a new motor!

Would agree with David , although some greases dont allow conductivity , but clearly this does , its designed to work with a small resistance and thats why its in there.

 

[David C]

Hmmm. This confuses me as grease is an insulator, wouldn't it break the conduction between contact and plate?

Google "contact grease" and have a read.
i.e.: http://www.electrolube.com/pdf/contact-lubricants-brochure-electrolube.pdf

 

[Nikolai]

Another 'in case anyone is reading this from a forum search in the future' post from me. I smeared some of the grease I packed back into the worm drive back over the contact plate as per the recommendations above, put the wiper assembly back together and refitted. I did take the opportunity to clear out the pile of compost in the scuttle and surrounding the wiper ecu. Everything back together and all seems ok so far.

I realised I don't have a rain sensor so that was something to rule out.