Frigidaire 5303917628 Defrost Thermostat (50°F) OEM Part

My problem first showed up as varying temperature in both sections of my old mid 1970’s Frigidaire model FPCI-170T-7 refrigerator, which is not listed on most appliance repair databases. Running on the warm side from time to time, as well as sudden fan noise (probably the fan blade hitting ice build-up on the evaporator coil) alerted me to a possible defrost system problem, since the compressor was cooling. The evaporator fan eventually failed after a day or so, and a major repair was needed. My evaporator coil is located on the bottom of the freezer, which seems more difficult to access than modern coils mounted on the back of the freezer wall. With the evaporator coil exposed (by sliding off the freezer bottom floor, following a day or so of being shut off) I could see that the coil was getting cold when I ran it for a few minutes, so the compressor seemed to be working. I found that the fan was burned out, as well as the drain heater wires located under the evaporator pan (not the separate defrost heater under the evaporator coil.) I am not sure if the drain heater recently failed or not, but water must have leaked through spaces in the evaporator pan to create a short circuit. The defrost heater had about 30-40 ohms which looked normal. I replaced the evaporator fan (P/N AP2592778), the defrost thermostat (P/N AP2592702) which probably caused the original failure, and the defrost timer (P/N AP2111929) just to make sure, since it was reasonably priced. The drain heater wires were expensive (if I could even obtain the correct ones) so I used the old repair trick sometimes called a “shepherds hook” which consists of wrapping copper wires (10, 12, or 14 gauge) carefully (since it was glass) around the evaporator coil heater and running one down the drain a couple of inches as well as two more wires sitting on the bottom of the pan to prevent freezing. I used 14 gauge wire, but would have used 10 gauge wire if my heater was not glass. I removed the evaporator pan assembly (with fan and defrost thermostat) leaving the evaporator coil in place. I also removed the defrost heater to install my copper wire modification. After replacing the evaporator fan and defrost thermostat, I also used plumbers putty to seal all holes and openings at corners of the pan to prevent any future water leakage. The repair seems to be successful and the refrigerator is working fine now. I am going to wait several weeks to make sure that the defrost cycle works properly, especially under different humidity conditions which may occur during normal door opening and closing. AppliancePartsPros.com was the only site I found that had the parts I needed and was more helpful than any other site I visited.