The defrost heaters are shorted to ground. No doubt about it. Unfortunately, I don't have a schematic for this unit. Here's my findings; one blue wire connects to the positive terminal of the top heater. Voltage appears at this terminal only when the defrost cycle is active. Two pink wires connect to the ground side of the heaters. The first pink wire connects to the defrost thermostat. The second pink wire exits out the back of the freezer and is the problem. I isolated the thermostat out of the circuit by cutting the (first) pink wire going to it. The ground was still present at all times through the second pink wire, including when the compressor is running or not or the defrost cycle was active. So in reality, the thermostat has no effect on the heater operation.


So the question is: The second pink wire connects to what part to control the heaters connection to ground?
The only general schematics I found on the web were no help and showed only one circuit from the heaters to the thermostat to ground.


What follows is only academic:
In confirming your diagnosis today I manually turned the timer until the defrost cycle clicked in, shutting off the compressor. The freezer air temp was -1.1F. According to the amp draw, the heaters turned on 7 minutes into the cycle.`The temp had risen to +3.1F when the heaters started.. The heaters showed constant amp draw for the next 42 minutes of the total 49 minutes of the cycle. The defrost cycle ended with the compressor starting and the amp draw dropping appropriately.

Freezer temp was recorded at 2 minutes intervals during the entire 49 minute defrost cycle. Sampling of temps after the heaters turned on: at 13 minutes; 44.4F. at 23 minutes; 59.9F, at 33 minutes; 62.2 F, at 42 minutes; 78.6F. Goes without saying, that's HOT.
Incidently, the freezer has been filled almost to capacity throughout this problem. Quite a pain to unload and reload.
After this problem began, the defrost timer was replaced with a GE part WR9X489 described as 16hr/35minute and the same part number as the old one removed. The defrost thermostat was replaced with a GE part WR50X60. The part number on the old thermostat is WR50X114 which did not appear in any of the parts lists for this model. So I have a timer that's running the defrost cycle 14 minutes over spec and a thermostat that is not cutting off the heaters. Your theory of heaters shorted to ground was right on! Meanwhile, the stuff in my freezer is getting almost cooked every 16 hours.



The part connected to the other pink wire is controlling the heaters and is the mystery and maybe the solution. Help!

Nope, no envelope behind the front panel. GE authorized service replaced the compressor some time back. I'm guessing it disappeared then. As for the
extra part in the defrost circuit, I'm tempted to cut the second pink wire and take this constant short out of the circuit. Seems like the defrost cycle would then be controlled by the defrost thermostat for a change. Cutting that wire would make the circuit look logical based on most defrost wiring. Still, one does have to wonder just what does it do!

Good job!
I'm glad you were able to fix it.

Gene.