Cannot unscrew cap on rinse aid compartment in door of Whirlpool Gold Quiet Partner III

There should be a port under the soap powder fill door with a screw cap and a red LED., Unscrew the cap and fill with liquid rinse aid.

TRY A RESET CODE
Press the "Sani Rinse," "Heated Dry," "Sani Rinse" and "Heated Dry" buttons on the dishwasher's electronic control panel in quick succession to put the appliance in diagnostic mode.
Close the dishwasher door and engage the door latch.
Wait 10 seconds before pressing the "Cancel" button to reset the dishwasher.

Just unscrew the little (blue?) cap next to the detergent container.

There is a small cap on the RH side of the dispenser assembly when the door is in the down position. The cap is usually round and blue, unscrews counter-clockwise 1/4 turn.

alot of people think the rinse aid is full but, its not. how to properly fill unit.
1. open compartment
2.fill with jet dry
3.close compartment
4.lower and raise door 3 times
5. open compartment
6.add more jet dry
7. lower and raise the door to see if it still looks full.
the reason for this is there is air in the dispenser and this process will take out the air to be completely filled the dispenser.

the rinse aid compartment has to be one of the biggest things in your unit. it helps with drying process or you will have wet dishes, helps with spots, and also with the cleaning process, this is what you can do . add jet dry or rinse aid not soap .fill compartment then close door ,then raise and lower door 3times then open the compartment door and add more repeat this process until you cant add anymore. this will pull all of the air out of the dispenser and allow you to fully fill compartment . the light should go off .

I did the same thing with my Maytag dishwasher, several times actually, before realizing I was putting blue dish soap in the rinse aid compartment which then wouldn't empty. Then my Maytag started making ominous noises during the rinse cycle (appliance guy said it was "cavitation" noise).

Appliance guy wanted to replace the whole detergent/rinse aid compartment but since he told me the noise was probably caused by the dish soap stuck in the rinse aid compartment, I decided to try to get rid of it first. Here is the method that worked for me; it took most of a day but saved me parts & labor:

1. Get some white vinegar--I used nearly a quart.
2. Fill the rinse aid compartment to brim with the vinegar (overfill) but don't put cap on
3. Raise the dishwasher door slowly until the vinegar drains into the lower part of the chamber (at least this is how my Maytag worked)
4. Agitate the contents as best you can by rapidly shaking the dishwasher door up & down.
5. I also used a small plastic medicine dropper jammed into small openings on each side of the rinse aid compartment to agitate the vinegar by squeezing air into them.
6. Drain the compartment by closing the dishwasher door (move it to full vertical)--vinegar will drain into the bottom of the dishwasher.
7. Repeat above steps a couple times, then fill again w/vinegar, put the cap on and let it stand for awhile. Then drain and repeat the whole routine several times.
8. Blue-colored vinegar will come out which is a good sign (or whatever color your dish soap was).
9. After awhile, I started pouring generous amts of very hot tap water thru the rinse aid compartment, alternating with white vinegar. (No reason you can't use hot vinegar also.)
10. Eventually, all the blue stuff came out & the see-thru levels of the rinse aid compartment were completely clear/empty.
11. Run the dishwasher (I decided to not put any rinse aid in). I got some overfoaming (from the washed out soap) the first time I ran it which I probably could have remedied by adding more vinegar & possibly salt, but the noises were gone!
I just ran the cleaned out dishwasher a 2nd time & it was back to its quiet self with no overfoaming.

Takes some patience but hey, beats a big repair bill!!

Most likely the actuator for the rinse aid dispenser is not functioning.

not good there is no way to drain it out. you might be able to take the door apart and take off the rinse aid reservoir and clean it out

jalexandruna the lid you opened on the dispenser that has 1-6 is where you pour in the rinse aid. As to if it will help or not, this sand issue may be hard water. Try using a eviromentally friendly detergent which is high in Citric Acid. Or try running a dishwasher cleaner like Dishwasher Magic thru the dishwasher to clean this residue out. Hope this helps