After the defrost I reassembled the refrigerator back and it actually worked better for a month then frosted back up. I checked the heater piece for continuity and the meter beeped so I take it as good, wasn't sure how to check the defrost thermostat on the coil, or the defroster control in the main compartment behind the unit. Also, how do you check the defrost control unit? Thank you.
Answer Hello Frank,
You need to begin the troubleshooting process with the unit frosted or at least after you let it run 24 hours. This is because the defrost thermostat can only be tested when it is below 20°F. Open the fresh food door and look at the control enclosure for a hole about 1/2 inch in diameter, (usually straight up). There will be a plastic "knob" inside the opening that can be turned with a small screwdriver. This is how the unit is advanced into the defrost cycle. As you turn it, you will hear it clicking. When it gets to the defrost cycle, it will click louder. Stop at this point. This is the beginning of the defrost cycle. Close the door and wait about two minutes. Now open the freezer compartment and look for an orange glow from the bottom "air grill" in the back wall of the freezer. If you see the glow, the defrost heater is energized and the issue is the defrost timer. The heater and defrost thermostat is verified good if the glow appears. If you don't see the orange glow, you need to remove the rear wall of the freezer compartment and test each side of the defrost thermostat for the 120Vac. If the voltage is on both sides of the defrost thermostat, it is good and you will need to use a resistance meter with power off to the unit to test through the defrost heater. Once you have located the bad part, you should allow the unit to sit in defrost with the unit plugged in for at least 45 minutes to make sure the timer cycles back out of defrost. This makes sure the defrost timer motor is good and advancing the timer properly.
My refrigerator has been working great for the last 11 or 12 yrs. What is wrong now is the storage area for the milk and other items is not getting cool but the freezer works fine. I found under it was plugged so I vacuumed out the stuff in the coils and around the fan area. I know the compressor is working because it is vibrating and the fan is working fine. So why is the bottom half not cooling off?
You will want to first check to make sure that the fan in the freezer is operational. If not then check to make sure that it is getting 120 vac. If it is then replace the fan. If the fan is working then check to make sure that the evaporator coils are not impacted with ice. If it is then it sounds like you may have a defrost problem with the unit. Check and see if there is any frost build up on the back wall of the freezer. If so, you will need to test the defrost heater and the defrost thermostat. They should read closed for continuity when cold. You can test this with a multi-meter TJMA-DMT3. I will include a link at the end to assist you how to use the multi-meter if needed. If both parts are good, you will need to replace the defrost timer. Once the problem is repaired, you will need to thaw out the ice on the coils before the unit will operate properly. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html