The wipers on my Fiat Scudo won't return to the 'park' position & won't work at all on "flick-wipe or intermittent".
They work on speeds 1 & 2 but won't "park"
I've had the motor off & cleaned the contacts/rings but to no avail.
I had similar problem on a Ford Cortina and found it was the stalk [operating leaver] the park contact current was not picking up so change the arm.
Worth a look at!