wiper linkage problem

installed a 74 WS on my 6. I wired it up, motor works fine, linkage seemed fine. I installed drivers side arm/blade...works great, installed passenger side, got a problem. It looks like the linkage flips over in a continuous circle instead of returning as it should normaly(only w/ arm/blade attached)
Anybody know if there's adjustments I can make? Or some other means of fixing the problem?
thank God for inline fuses...when the arm should have returned it didn't, instead dug into the cowl until the fuse popped
Jim S.