1999 Mitsubishi Montero Front wiper motor

If it stops in the same place all the time, then you just have to shut it off at the end of its cycle, and remove the wiper linkage from the motor and put the wipers where they should end up and put the linkage back on.
If they stop where ever they are when you turn them off. That could mean that the wiper motor mounting plate lost its grounding. You can test this by just using a wire to jumper from a good ground on the engine compartment to a mounting screw (scraped off) on the wiper motor mounting plate.
If it works now, just do some scraping to get the plate to make a good ground or put a grounded wire from the engine compartment to a screw that is used to secure the wiper motor plate.