wipers not working
 

I have a 2003 ford f-150, I recently had a new wiper motor installed in the truck. Now wipers act funny when put on timed/delay. When switch is clicked forward to be put a delay. The wipers only bump forward a foot or so. The wipers don't go through a complete sweep. Then when the timer goes to make another sweep, they only bump forward another additional foot or so. But if the switch is turned to be put on continuous then wipers make full and complete sweeps and work great. I need help to figure out why wipers wont work when put on timed/delayed?