I hope this is of some help! The wipers on my 1999 306 recently started
to 'stutter' when about to park, either from switching off, on rain
sense or just single wash/wipe. All Peugeot user's web sites showed
this as a common problem, with both dealers and owners blaming water
ingress.

My wipers ran OK when switched on so I wsa confiden they would not let
me down. I left them to let the fault develop into something
repeatable. I was definitely the self parking relay contact within the
motor. It was about one hour's work to remove the motor and open it.
The relay consists of three metal fingers, value about 0.5p, one of
which had burnt short my spark errosion. Two needle nose pliars were
all that was needed to reshape the end and refit. The wiper is now as
right as rain! The work was simple, nothing will fall out of the motor
when you undo the cover (4x small screws).

Tools needed: simple gear puller to remove wiper arm (mine were stuck
on the spindle) Do NOT try and lever them off else you may crack your
screen!. Allen key/Torq blade to remove plastic trim, assortment of 6,
10 and 13mm sockets/spanners, two pliers. Saving £100 on new motor.

What is needed now to prevent this happening again is to use the
internal contacts to control an external, high current swtiching relay.

Ah, but Peugeot would far rather you bought a new motor :)