Hi,
When a dryer takes to long to dry it is because of some kind of air flow problem.
Check your dryer vent first. Also go outside and check the hood on the end of the dryer vent.
If your vent is clean then you need to take a look inside the dryer.
You will need to remove the back of the dryer and the blower housing.
Your KitchenAid dryer is made by whirlpool.
Here is a video that will show you what to do along with some detailed photos of just were to look for the lint buildup.
The front of the whirlpool dryer in the video may be a little different, but the back of the dryer is very much the same as your kitchenaid model. Video & Photos
Good luck with the repair.
AJ | 
Kitchenaid dryer 
