Fisher & Paykel DD601 top drawer won't start. When start button pressed dishwasher just makes a beeping sound and will not start. Bottom drawer works normally. Any help appreciated.

you will find this diagnostic service document useful.

http://applianceassistant.com/ServiceManuals/dishwasher-fisher-paykel-dish-drawer-dd603-ds603-service.pdf#zoom=100#scrollbar=1

The likely reason for top drawer not starting wash program when you press start button is the drawer home sensor is either faulty or the drawer is misaligned. This means controller thinks the drawer is open and does not start the cycle.

Assuming the bottom dishdrawer is working ok, it is likely the controller on the top drawer is either faulty or sensing some incorrect signal. If pressing any of the panel buttons makes no difference, then most likely the controller is faulty.

By the way I am unclear why you mention two models in your problem description. DD603 is a double drawer dishwasher and DS603 is a single drawer unit.

It is very likely the two problems are not linked. Use small quantities of power detergent (Finish works best) to avoid foaming. The foaming usually triggers flood switch and shuts dishwasher. If the beeping is constant then most likely the flood switch is triggered. But if you get one or 2 beeps when you press start, then it is likely some sensor in drawer is faulty. Usually the drawer close switch is not working.

There could be several reasons for the beeping. The dishwasher checks for sensor to make sure it is in good health before it starts. Most likely the drawer close sensor is detecting fault. This is to ensure the drawer is closed fully to avoid water leaks when dishwasher is on. Sometimes sensor itself has failed and has nothing to do with position of drawer. Open top cover carefully to make sure the drawer is travelling ok on the rails. TAKE MAINS POWER CABLE OUT BEFORE WORKING ON DISHWASHER.

The dishdrawer is a very sophisticated dishwasher and is very sensitive to dirt collecting inside and in the drain hoses. My suggestion would be to first clean the drawers from inside with damp cloth, especially around the top panel. Buy Finish dishwasher cleaning kit (one for each drawer) from the supermarket. Select longest cycel on dishwasher and run each drawer with the cleaning kit inside as per instructions on the kit.
See if this makes any difference.

here's the manual..
i did not read thru the whole thing but there are quite a few removal items that i'm sure will lead you to drawer removal.
Hope this helps you.

https://www.scribd.com/doc/6462163/DD601V2-Manual

First is to make sure there is no leak. Pull out the lower tube, access from the left side only this side you can put your hand in with a small tower to dry out the wetness if there is. If it is wet dry out really good then unplug the power cord for 24 hr. After that plug power cord back. Hold the lock button while press the Start button until you see a display appears. Press the Power button to see a clear display. Then hit Start button one by one until you see Ld ( it stands for Lid down) If you miss it, keep going until it comes back in a loop. When at Ld hit the lock button. Wait until the noise is stopping. Hit the lock button again. Wait until the noise is stopping. Now you can pull out the top drawer and press the power button to get out this manual mode. Good luck.

I can talk you through finding the fault on live chat. cheers

I suggest pressing the keylock and power button together, hold for 5 secs, the display will change orange, the display should read HP if it says LP, press the start button to make display read HP.Then press power button to store. You will need to manually removed the water from the machine before restarting