wipers stop at 12:00 position when off?

[kauaiman]

could use a little help, 1964 c10 step side and windshield wipers work ok but always stop at 12:00 position instead of stowed position. i have a factory manual that shows that the index marks for the wiper motor and mine look correct when in park position. the factory ground strap is also attached, so i can't figure out whats going on. motor appears to work as it should? any help would be appreciated. Thanks