1997 300 tdi wiper wont switch off when stalk is switched off

hi everyone i think the wiper stalk on my defender is knackered any know if i right as the the wipers will not turn off when the wiper switch is off

It could be the stalk switch or the park switch.
The stalk will give power to the wiper motor to start it but when you switch off the power is held on the motor until the wipers reach the park position,
When in the park position the park switch is activated by a cam mechanism attached to the wiper motor gear, if for some reason the park switch is broken, out of position or just a wire off the wipers will keep going.
Check this switch and wiring as well do not just go out and replace the stalk switch.

cheers mate