GE freezer section too hot on defrost

Refrigerator & Freezer Repair
1

GTS18ICSXRWW
I have dozens of GE residential top freezer/bottom fridge units where I work. I monitor the freezer and fridge sections separately. I see a common trend on the thermometers.
The freezer sections always show that at some point they got really warm, up in the 40s or 50s.
I’m assuming its happening during defrost.
I’m working on one now. I replaced the temp controller, the defrost timer and defrost thermostat. It seems to still be doing the same thing. I even tried a lower temp defrost thermostat to try to kick it back on sooner.
WR50X45 is what I have in it now. I was hoping that would do the trick.
Is there a guide on line that gives info on these thermostats and breaks down when they kick on and when they reset?
I used new parts from a local supply house.

Any ideas?

Thanks!

3

defrost timer bad?

4

I have an ohm reading on the two middle pins. And nothing on the two on the right. Advance the timer and this reverses. My understanding is that this timer is good.