1974 dart wipers stopped working

[Aragon6640]

Thank you all in advance. I have a 1974 Dart that the wipers recently stopped working. It seems they get power (dash lights dim a little) however no movement from the 3 speed wipers. Is there a way to determine if it's the switch or the motor?

 

[CFD244]

Check the grounds. There is a strap on the motor, and IIRC the switch body needs to be grounded as well.

 

[Car Nut]