I can understand your need to know where the defrost timer is located on your refrigerator. I did some research and provided a link to a similar question and answer on our site. I hope this will give you a better idea where the part will be located until the Expert responds to your question in more detail within 24 to 48 hours.
Thank you for your question. The defrost timer in this model is built into the control board # W10165748. I'm attaching information below of how to place this control into the defrost cycle. I hope this will help you. If you would like more assistance, reply to this thread and I will be glad to assist you further.
Thank you so much, I wonder if trying a forced defrost will kick my refrigerator back on...the freezer stopped freezing (though it stayed cool) and then a day later the refrigerator portion stopped cooling. Someone suggested I try a forced defrost to see if that will somehow 'reset' the refrigerator and freezer to start working again.
Kathleen, the only way to reset the control will be to, disconnect the power for 30 seconds and then reconnect it. If it still won't start running again, the control # 12868513 will need to be replaced. I hope this will help you.