I have a KitchenAid under the counter ice maker and after 6 repair calls, two different services repair companies and $500 later the ice maker would only make a hand full of wet ice. The last repair company said they could not diagnose the problem.
I decided to take on repair myself. I inspected and cleaned the fill water valve and found some debris on the valve seat. The valve tested good at 275 ohms.
I cleaned the evaporator plate and the cold water circulating system. The ice maker will now make about a half a bin of wet ice in 12 hours. It appears the grid cutter is taking a long time to melt thru the ice.
I then removed the grid cutter and it tested good at 5 ohm. I checked the dual transformer and it’s different from the one shown in the repair manual. The repair manual I have is for model KUIA15NLHS11 and my unit is a KULA15NLHS6. This means five engineering changes have been made to this unit. The dual transformer shown in the manual has one plug with 6 wires and mine has four stabs and a ground screw. The only ohm reading I get is from the 115v in and common white wire stabs ( 17.4 ohms).
I need help on how to troubleshoot this dual transformer along with and other ideas on how to complete the repairs.
Thanks
Jim

New up date.

I have cleaned the evaporator plate and the cold water circulating system again and started the system. After the system went in to the harvest mode about three times the first sheet of ice is still on the ice cutter grid with the next sheet on top of the first. The unit is making a sheet of ice ever 30 min.
I also checked the bin thermistor with a ohm meter, with the themistor in ice water for 5 min and the water at 32.2 deg f. I only had a resistance of 25,400, not the min. of 30,266 and a max. of 36992 per the repair manual at 32 deg. F. The manual states for 50 deg f the resistance should be between 18,218 and 22,267.
Could I have two problems the first the cutter grid not heating up to the desired temp. and second the bin temperature is to high.

Again I thank you any help you can give.

Still looking for some help on troubleshooting my ice maker

I too have the same problem ... the cutting grid isn't getting hot AT ALL!! I replaced the grid with a new one ... still nothing. The transformer is is a four post like yours. 110 coming in and 8.5v out. This transformer is actually putting out a little more than that .... but apparently whatever controls it coming on isn't working. The ice sheets just sit there .... I'm guessing a bad board??? but then I'm just guessing....