wiper switch grounded ?

[Nacho-RT74]

does need 3 speed switch to be grounded to make work properly the motor ? I'm pretty sure 2 speeds switch doesn't need.

I'm asking this because didn't made t work properly the wiper motor ( is used but does look good ). I never removed the old 2 speeds switch, was simply trying to making it work hangig out from plug down the dash and when I was touching the switch and any part of the car body I was feeling I was grounding ( got small shocks )

[konigcharger]

yes, the wiper switch needs to be grounded