My dishwasher is only one year old.my spinners suddenly stopped spinning

Check the alignment and contact surfaces. Any bearings that allow the arm to spin when cold, may tighten up when heated and cause the arm to slow down or stop.

water is not circlating, you need a circulation pump

Hi.

First ensure that the arm is not getting stuck, and check that the orifices are free.

When the top arm is not spinning you may need to replace pump and motor assembly. First it is good looking for blockage in pump hose.

If the appliance is less than two year old, then it may be covered by limited warranty. Call Kitchenaid at the number listed in the owners manual to verify your warranty status.

Regards.

The top spinner part can simply be pulled off by grasping it near its hub and pulling downward. Push it back on and push in the locking clip in the center. The bottom spinner can be removed, First unscrew the center column. Hold the spinner with one hand, turn the base of the center column counter clockwise. Then lift column off. Then the spinner should lift off of the keyed white plastic base. Underneath it, on the neck off of which you lifted it, are two plastic washers that form a seal (supposedly). Good to clean these to make spinner rotate freely, but be careful not to break them taking them off. If you want to go farther in, there is the point of a strange shaped plastic nut sticking up into the base of the column. If you remove this, and the 6 torx screws holding the strainer cap, you can get it all out to clean it up (I had bits of plastic bag in the slots of a 4-armed thing that apparently sprays the filter screen), and scrub the washer in the bottom. Remarkably yucky down there in a 10 year old installation...

Make sure that the spray bar when lifted by the water pressure is NOT hitting the dish rack OR has excessive friction. Test by manually lifting and turning.

Also the jets must exit at an angle to provide the torque.

First, confirm that the holes are not blocked on these arms. (I did not want to assume you have done this.)

Then check the impeller on top of the motor stem for being loose or worn/damaged - to rule the impeller out. If it is fine, then the motor is failing and too weak to drive the spray arms.
To answer your question, I think the answer is "They don't make them like they used too!"

Try twirling the spinner by hand to see if it is binding. If it looks ok then there could be something plugging the water passage to the spinner. If you have access to a water hose you could run water into that verticle passage pipe and see if there is an obstruction. If so it can be taken apart for cleaning.

The problem is insufficient water.
There are a few issues that cause this, and most are pretty easy to fix. Check this site for instructions and pictures:


Dishwasher Repair Tips Dishwasher Not Cleaning Dishes

change the spinner switch

Take the impellors of (inside machine) and check to see if there is anythig clogging the wholes. Run the machine for a couple of minutes without impellors on and check around the sump and filter.