Typically, a mechanical defrost timer is used to control the defrosting time sequence of the freezer. In previous models, the timer would run consistently. In every six hours, it would cut the supply of power to the cooling system. Later it would send the power to the defrost heater.
On the contrary, in the newer versions, the timer will advance only if the compressor or the defrost cycle is working. At the time of progression, the power to the heating element will cut, and power would be restored in the cooling system.
In case, the timer doesn’t advance; the appliance will remain either in defrost or refrigerator mode. As a result, there would be or frost build-up.
So, in this post, we have come up with the idea of telling you how to test the defrost timer. Therefore, after reading the post, you would be able to test it on your own quite easily. Let’s start reading the post and make things easier for you!
How to check the defrost timer on your own?
At first, unplug the refrigerator for avoiding any electrical shock or accidents. You will see the defrost timer behind the front grill – ‘toe kick’ of the fridge. You might also find it behind the cover plate within the freezer, behind the refrigerator and adjacent to the compressor, and in the temperature-control console.
To figure out whether the timer is unable to advance; you have to find the advance screw first. And then just turn the screw clockwise till you hear a click from it. This click will be an indication of the progression of the subsequent mode. For instance – if the previous one was in cooling mode, it will now be in a defrosting mode. After all that, you have to wait around 35 minutes to see whether it has resumed its position in the cooling mode (listen to the sound of the compressor).
Step-by-step to an Electronic Test of a Switch
If there is no advancement, it will be apparent the timer is bad. For that reason, you have to change the timer entirely. However, if you find that it has advanced just like as it is expected, you should follow the below steps for electronic test of the switch –
Usually, the timer is held with several screws. Therefore, you should remove the bolts and pull the timer out. Make sure the timer is kept in a long distance from it. It will make sure the wiring connector is disconnected. You can remove this wiring connector if you pull it firmly by shaking it in the left and right directions. Note that the location of the wires is not significant as the connector’s plug is keyed for replacing it in one way.
Using a multitester, you can test the continuity of a timer. For this reason, you have to fix the multitester to the ohms setting X1. There are four terminals in the timer, and you need to find the common terminal. The common terminal is labeled like – “3” or “C.”
When you have found the common terminal, you need to touch one probe to it. Simultaneously, you will touch the other probe of every three remaining terminals. It will then show a reading of either zero or zero ohms – indicating continuity. Remember this reading is for one or two pairs of the terminals. The third pair will not show any continuity.
Now, you will find the switch of the timer and turn it to clockwise. You will wait to hear a click from it. At this moment, you will test the timer for the second time like the way we did above. One of the pairs would show continuity (might also be two pairs). And one paid would indicate a reading of infinity as well. Keep in mind the paid that show continuity will show infinity and vice-versa. In case, the defrost timer fails to pass these tests; you will likely change it to a new one.
To conclude, we have discussed the mechanical defrost timer’s control mechanism. So, if you mix it with electronic or adaptive defrost controls, it would be a big mistake. Not to mention, we have explained how you would be able to test a defrost timer as well. So, if you follow the above steps and procedures correctly, you can check the defrost timer entirely!