> Without any evident cause, my rear windshield wiper arm stopped
> working and the arm just sort of flops around.  I thought that
> jiggling it by hand might reengage it, but it had no effect.  Does
> anyone know if there's a simple fix (e.g., a shear-pin or breakaway
> mechanism in the shaft), or must I replace the whole unit?  Thanks for
> any info you can provide.