Wiper motor test

[Danman09]

I removed the wiper motor from the 1970 C10 project I bought while I am replacing the dash harness.
I looked here and found the bench test steps and tried it. When I ground the case, put power to the power lug, the motor runs without providing a ground to either the high or low lug.
So I take it that the motor is bad even though it runs ?
Just wanted more opinions than mine before buying one that is probably an inferior product to the original.