GE Monogram Small ice streams run down left & right sides of freezer

[GE_JUNK_OWNER]

My three year struggle .....
Small ice rivulets run down left & right sides of freezer ... I've determined the ice maker is not leaking by turning off the water supply for several days and I still have the problem ... the water comes from the evaporator area above the ice maker.
I've also shut the entire unit down for several days to let everything melt (also used a hair dryer) and dry out  ... and within a few months same problem is back.
I'm in far northern WI ... I've called GE for a serviceman ... they told me to go to the Yellow Pages ...
The freezer seems to be working ... if I leave the ice maker run I get good ice cubes ... food seems adequately frozen ... although I have not put a thermometer in the freezer...which I will do ...
Is there a drain that is plugged ... where is it ... how do I get to it ... in the back ?
Or do I have some type of excessive defrost cycling problem?
HELP

Model ZISW36DYA

[niobrara]

You have a drain pan under the evaporator with a drain tube going out of the pan.Pan could be plugged or the drain tube frozen.Look at the diagram for your model,remove the covers to get to the drain pan and tube.

[jumptrout51]

http://www.appliancepartspros.com/partsearch/model.aspx?model_id=231800&diagram_id=20742226#d20742226

[JWWebster]

Ice or other things will block the drain. Under the bottom of these coils is where that water must go. if it don't then it ends up puddling inside the ice box. Click on pictures to enlarge

[PARTech]

Click on jumptrout51's link, part number 17 is a defrost heater for the drain pan and bears checking along with the defrost thermostat.   If you look at the schematic you can check the circuit at the plug just to the right of the brace shown in the link.  Your schematic should be in the envelope behind the top vent panel.