Intermittent Wiper Fault

[greenskinned monster]

Hi All. has any of you had this happen? my windscreen wipers seem to have a mind of their own and on occasion its like they have forgotten how long they run for (on intermittent-that is) or where the "park" position is.when on intermittent they stop mid screen on sweep back-then do another 2/3 cycle etc. if I pull the stalk back to wash the widscreen the minute I let go of the stalk the wipers stop wherever they are on the screen, likewise if the wipers are turned on either lo or hi. Also if I nudge the stalk up to do a single wipe they only move while the stalk is held up.On the Not so random occasion it does this, if I switch the stalk up and down rapidly several times it seems to sort itself out-until the next time. I have had the wiper motor plug apart and cleaned it out, and the stalk itself seems ok-Suggestions anyone? I'm contemplating the BEM but ??? My ride is a BA2 XR6T ,has premium ICC with dual zone A/C,and auto lights option. I have also tried taking the Battery off etc and draining all power from systems then reconnecting it but it never seems to fix it

Cheers in Advance