Wiper motor runs slow?

[BrugeeRT]

So I am putting together a 68 and am trying to get all the electrical figured out before putting the cluster back in.  My latest challenge has been the two speed wiper motor.  The problem is that it seems to be running slow (not connected to the linkage) it takes almost 7 seconds for the nut to turn in a full circle and switching the higher speed doesn't seem to make a difference.  Motor runs fine doing a bench test with the like new battery, its when I run it through the switch and cluster it slows down.  The manufacturer recommends 5-7 amps for it to run properly and I seem to be getting 4-5 amps.  I tested the continuity between the different points on the switch using the service manual and that seems to be fine.  There was no ballast on the old or new wiper motor, the two brown wires were just spliced together.  Would this effect the speed or the lack of the higher speed?  Any ideas why it would be running slow?  Thanks for any input.