Defrost timer testing

Refrigerator & Freezer Repair
1

Hi:
I have read many of the postings on the problem I am having–
Freezer is OK, but refrigerator is “warm”. The heater coil and thermostat are both good. But I am not sure How to test the Defrost timer..
So, I ordered the defrost timer and replaced it… But now the Compressor does NOT turn on. Replaced the “New” timer with the “Old” timer. Compressor works fine. So My question is How do you test the defrost timer..? I have a few tools— digital multi meter etc. Thetimer has 4 terminals .

The original problem— Frrezer is fine , but refrigerator is warm showed me the Coils were fine-- No build up of ice. fan is fine.
What else can be wrong ? and how to diagnose the issue ?
Thanks
padaki

2

With a flat bladed screwdriver, turn the timer till it comes out of defrost.

3

Will the Compressor come on If I just leave the refrigerator plugged in ?
The timer should end its cycle, right ?
What happens to the heater coil…? No ICE build up, but Timer is ON. Will this damage the heater ?
Thanks
padaki

4

It should come out of defrost eventually if you pluged it in right.