Dead Front Wiper Motor?

[Tardis]

Older Toyotas often seized up their wiper pivots. The motor was generally ok it just could not overcome the stiffness of the pivot shafts. Not sure how it works on the Yaris with its wiper "assembly" but if the motor is removable it may behoove you to see if the rest of the assembly moves freely once removed. Possible lubrication might be the solution. If that is the problem a new motor won't work any better.