406 faulty wipers

hi i have a 1999 v reg 406 exec hdi 110. (face lift model?).
The wipers only work ok on the slow speed. The fast speed will work
some time but will not work if the slow speed has been in use for a
time. The wiper blades stop as soon as you switch to fast. You have
to keep the switch on to do a single wipe and release when wiper is at
the bottom of screen (wont self park). Start screen wash - washer
works but wipers dont move. Bought a new motor but wont fit as this
is a mk2 motor.
Do you think this is a motor fault or are there any relays hidden
somewhere or is it a steering column switch fault.

 

Many thanks for the info, I’ll try the stalk for faults. I was not
aware of the problems with the stalks on the MK1 cars. Since checking
and cleaning the loom to wiper motor connector the wipers work on fast
speed as well as the slow. The other faults remain but no trace of
water in wiper motor.
Cofi