Pinto Car Club of America

I am trying to install an intermittant wiper setup into my 73 Pinto. The setup came out of a 77 Pinto Wagon. The problem I have is the wiper motor will not reset to the unused position when the switch is turned off. I think it did the same thing with the original switch. I will reinstall it tomorrow and see. Also the intermittant does not work. When switched on intermittant, the wipers run constant and are on low. I have the switch ground, grounded but the relay box and switch are hanging. Does the box need to be grounded? Do you think I have a problem with the motor? Do I need to change it to a later model one? I remember reading some where that the wiper motors were different between the early 70's and late 70's cars. I have also read that this is a simple swap for the 69-73 Mustangs? Any help would be appreciated.