The defrost thermostat went bad on my 10 year old Admiral 21 Cubic Foot refrigerator model LTF2112ARW. I knew that because there was no continuity between the white and orange wires when the thermostat was submerged in a cup of ice water. There was also heavy icing and frost on the back wall of the overhead freezer compartment, and the refrigerator below was not cooling. When I looked for the necessary replacement part on the web, 63001599, every place I went said that the part was no longer available.
Hoping to keep the fridge alive, I saw that the broken thermostat was labeled KS-2N-MF, with a rating of 16.2/-5.4. When I Googled the part number, I found it was made by a Korean company, and all the specifications for the part, including a schematic were found here: http://www.pnacorp.com/mobile/sub02_08_01.html
Looking at the specifications and schematic, the original three wire thermostat included a small thermal fuse (73C-84C) as well as a 60 degree F/16.2 degree C thermostat inside the sealed black casing. The original part has three wires: a white wire, an orange wire and a brown wire. The brown wire actually allows current to flow to the defrost heater when the thermostat is closed, and when the temperature in the evaporator area near the thermostat exceeds 60F, the thermostat opens and shuts down the heater. The thermal fuse is evidently there to protect the system from a heater malfunction, and resides between the white and brown wire based on continuity testing and the schematic.
Before disassembling and reassembling the refrigerator, I unplugged the unit.
To replace the unavailable part, I purchased the components of the thermostat and made my own.
Here are the parts I used:
- Supco ML60 thermostat. This thermostat opens at 60F and closes at 40F. The original thermostat opened at 61.6F/16.2C and closed at 37.7F. (a 22.3F/5.4C degree range). This was available for $2.95 at McCombs Supply.
- Supco SL247 clips for attaching the thermostat to the evaporator tubes. ($2.70 for a pack of 3 at McCombs).
- A Microtemp 73C thermal fuse on Ebay. ($2.50)
To make the part:
1. Take a picture of the original installation
2. Cut off the two-conductor, white plastic connector with orange and white wires, leaving about 3 inches of wire coming out of the connector.
3. Slide a piece of medium size heat shrink tubing over the white wire, from the white connector almost up to the end of the wire cut. Strip away the insulation on the white wire, and crimp it to one side of the new thermal fuse using a small size crimp connector suitable for 16 gauge wire. It doesn't matter which end of the fuse you connect to the wire.
4. Cut off the entire length of the brown wire from the old thermostat.
5. On the new part, crimp the brown wire and one of the new thermostat wires to the free end of the new thermal fuse.
6. Pull the heat shrink tubing over the new connections, and heat the ends of the shrink tubing to seal the connections. Don't heat the ends too long, and don't shrink the tubing over the fuse or you might blow the thermal fuse.
7. Slip a short piece of heat shrink tubing on the free orange wire and crimp connect the orange wire to the remaining wire from the new thermostat. Pull the heat shrink tubing up over the new connection, and shrink it tight over the crimp.
Here are some pictures of the new part before applying the shrink tubing:
|Finished part with connections covered and heat shrink tubing ends sealed. You can add some silicone sealant to the ends if you want.|
To finish, I attached the new thermostat to the evaporator tubing using one of the new clips. Route all the wiring towards the back of the freezer box, behind the existing evaporator tubing. Plug everything into the connectors in the evaporator area. I reassembled the freezer compartment, icemaker, etc. and plugged in the refrigerator.
Here's a picture of the new part inside the freezer/evaporator area:
|New installed thermostat and thermal fuse unit with wires tucked behind the copper evaporator tubing. The new thermostat just clips to the tubing where there is covering to prevent a dissimilar metals interaction.|
This fix worked for me in replacing the no-longer-available 63001599 Korean three wire thermostat. The total cost for parts was about $15.00. The refrigerator is now cool, the defrost cycle works well, and I hope to get another 10 years out of this appliance. It is so nice to have cold milk again.