Defrost Timer

I troubleshot the problem by reading the electrical schematic and concluding the heating elements (defrost cables) were either defective or the bi-metal temp sensor was open. When closed the temp sensor completes the circuit for the current to flow through the heaters to defrost the cooling coils every 8 hours and then when the bimetal opens at 55 degrees the circuit is open and the coils are cooled because the refridgeration motor is in run mode. A timer between the motor and heater elements also was defective. The timer controls the cooling period and the defrost period. I ohmed out each part according to the spec sheet of normal resistance of parts and thus the bimetal and timer were defective. I gather a surge of some duration and amplitude affected these parts because a storm 24 hours prior to refridgerator problem had passsed through the area and the AC electrical power had oscillated several times during that event. I used hand tools to do the repair. If you are not mechanically inclined a step by step proceedure would be moot. It is a matter of disassembly and assembly paying close attention to fragile parts.

A. remove food from freezer and store in cooler etc.
B. turn off frig with dial in main compartment, then pull frig out away from wall and unplug and remove the cover ( It is located at the bottom of the frig and may be cardboard and contains a handfull of 1/4" screws) exposing the compressor and drain tube (this is a good time to vacume the compressor and coil area)
c. Take false back off from freezer by removing two 1/4 inch screws.
Next,
1. we made sure that the drain tube that runs down to a drain pan near the evaporator coil was clear, we did this by using a small aount of rock salt to speed up the melting of the ice then poured small amounts of hot water (boiling into the drain hole and soon the water flowed down the tube and into the pan below.
2. We then pushed a #12 standed electrical wire (with its end stripped back 1-1/2" then folding the strands back to create a broom) down the tube to the pan to push out any debree that may be present i.e. tin foil plastic bag particles, food chunks etc.
Making sure that this drain tube is clear is the first thing that could be causing the ice build up and water in the lower compartment!
However, I performed this several times and didn't change the problem so I chose to change the parts associated with defrost:
1. defrost heater, which is very easy to change. it is mostly plug and play but does require a pair of needle nose pliers to open a couple of metal fins to remove heater from its mounts, just be gentle with the process.

2. defrost thermostat, which is also very easy to change (Simply pull it off of a copper tube) but requires you to cut two wires near the old part and wire nut the new part wires to the remaining original wires, I added some anti oxident to the wires inside the wire nut to prevent a bad connection from developing do to moisture in this area (You can buy wire nuts with this already inside them, do this)and I taped the wire nut with a few inches of ELECTRICAL TAPE CLOSING OFF THE OPENING OF THE WIRE NUT.
You can then put his cabinet back together!
3. I also decided to change the defrost timer which is located inside a cover where the frig temperture setting dial is located. It is held to this cover by two phillips screws the cover is held in place by one 1/4" screw.
once you have the cover off and the defrost timer unscrewed you must remove a plug from the timer!
Now if you got the exact part you simply reinstall the defrost timer plug in the same postion on the new timer and screw the timer back onto its mount etc. However you may need to determine if the new timer is in the "DEFROST" position and you will need to take it out of that position by I assume rotating the timer mechanism (Ask a tech person about this)!!!!!!!!!
Then with all that done plug your frig vack in reposition it turn it on and be proud of yourself.

Now, if you recieved the timer I did it may look the same as the old one, but it may contain a black wire!!!
You will need to know which type of defrost timer application you frig uses:
1. Continuous run
2. version 1 Cumulative compressor run.
or
3. version 2 Cumulative compressor run.
I found a wiring diagram folded up and stored in the grill in the bottom of the front of the frig that helped me determine this. you will need to be able to read a wiring diagram but I found this situation to be simply a matter of matching examples of pictures (line diagrams). It is important though as you must determine which timer application your frig has because the black wire must be placed on a certain terminal for proper operation.

I replaced a three parts and may have, through trouble shooting, been able to save some money by not replacing all these parts. However , I found that when I went for guidance on trouble shooting that i.e. with the heater that ohmic values of the old part may be near the new part that it may still not be conclusive!? so for a hundred bucks my frig may last 5-10

Trouble shot the electrical circuit per the electrical schematic and zeroed in when I noted the Defrost Timer circuit was open. When I tapped on the bottom of the timer it began functioning normally (for a few days). Ordered a new Defrost Timer Kit and along with the installation instruction, I watched the on-line video. It was very helpful!!
After installation was complete, I plugged the Refrigerator into the electrical outlet and.......nothing happened! Hmmm!

Removed the Defrost Time Kit and inspected it for any damage and found none. Then I placed a flathead screwdriver to the manual advance knob and slightly rotate the gear mechanism. I heard a distance "click”. I believe the Timer was in the ‘defrost’ mode when received.

I reinstalled the timer, verified the wiring connections and this time plugged the Refrigerator into the electrical outlet and ….. it worked!!!

I unplugged the refrigerator, finished the installation per the instructions, plugged the unit in and monitored it for a few hours (just in case). That was a week ago and the Refrigerator is working like new.

The instructions were written in a manner which required re-reading a few times as they could be a bit vague. The video was what really helped and I appreciate PartSelect adding it to the instructions.

De-iced the refrigerator. Removed two screws from the thermostat panel on the upper refrigerator section. Tilted it down, removed two speed nuts holding the timer, unplugged the timer plug. Determined from the instruction sheet (easy to follow) what time delay function is used, based on wire colors, placed the jumper on the correct terminal on the new timer. Plugged it in, replaced the speed nuts and screws. The timer fit perfect, works just like it is supposed to, quick easy job.

First I replaced the thermostat that I had ordered thru Partselect but that did not seem to effect the reair. According to the schematic diagram the only other thing in the circuit was the defrost timer. Immediately on its arrival I went to the refrigerator and removed the two screws that hold the timer in place and disconnected the two wires and installed the new one from Partselect in reverse order. It took about 15 minutes and it was back to running.

Unplug the refrigerator first,then Remove shelves and back inside cover from the freezer. Cut old bi-metal thermostat off and installed a new one. This fixed the problem. Ordered a new timer also which I didn,t need but installed it any way. On the fridge side ,top front, removed the knobs and cover, R&R timer, installed cover and knobs. Pay close attention to the instructions on where to put the black wire on the new timer. My refrigerator works great now. This was easy to repair if you are handy with electrical and mechanical repairs, if not get some help.

1. Unplug refrigerator to remove power!
2. The timer is inside the control housing located at the top of the refrigerator compartment.
3. Remove two control knobs (the pull off).
4. Remove the front panel escutcheon. The panel is not held in place with screws, but can be gently pried off.
5. Remove two screws from the back that hold the housing in place.
6. Remove screws from the front that hold the housing in place.
7. Drop housing down (still attached by wires - do not detach). Timer is inside housing, located on right.
8. Follow the instructions provided to identify your particular wiring setup. You'll find the wiring diagram (on my model) at the bottom of the refrigerator, alongside the defrost catch pan, behind the airflow grille.
9. Remove connector from timer terminals (4).
10. Remove two screws/nuts that hold the timer in place.
11. Install replacement timer following included directions. Read and follow ALL instructions applicable to your particular model and wiring setup.
12. Reassemble by reversing the steps above.
13. Note: You may need to "jog" the replacement timer when you first plug the refrigerator back in, if the timer happens to be in a "defrost cycle" (the compressor won't start). This can be done by inserting a wide bladed screwdriver into the hole below the timer, aligning it with the timer shaft, and slightly turning the shaft CW. Don't force it, and don't turn it very far.

Just removed the old timer and attached the wires to the new one and replaced the old. That simple!

first thanks to part select for the info in the web site.last week notice the area in the refrigerator.was bearly cold. went to parts select read the coments.and whala.i am an expert.my wife was amazed.i was sure the evaporator fan not work,but reading in the web site i learn it can be few other parts so a change all 3 parts,just to make sure, thank you again part selact you are the best.and thank you for the magazines.. JOSE ANGEL

tested thermostat and defrost time but both tested as working...called a repairman who came in and said they were both working...got annnoyed for not trusting myself. Repairman did say that he had seen defrost timers simply slow down, allwoing them to tesat as good but not actually working correctly. I ordered both the thermostat and the timer to cover all bases...actual replacement was simple.