Fridge stopped running. Both freezer and fridge do not cool. The compressor is silent and cold. Light comes on when the door is opened, so power is getting to the light and thermostat assembly.

I found no service manual for any Zanussi fridges. There is a (apparently useless) user manual for model ZD 19/4. My model is Z 19/4 D, which archive.org does not have the manual for.

Anyway, I pulled off the relay switch and took these compressor measurements:

        ° common
start °   ° run

common-run:    14.3 Ω
common-start:  19.3 Ω
start-run:    ~33.3—34 Ω

Ytubers quote values of ¼ of what I am measuring. They are demonstrating on different models of course, never my model, but they speak as if their measurements are a norm. My start-run resistence is the sum of the other two measurements, which is the one characteristic that is claimed to be correct. But are my resistences all too high? I used 2 different DMMs to confirm.

I hot-wired the common and run terminals to the house mains. It made a hum sound. Then I jumped the start winding to the run winding and the motor started. From there, it runs fine. Sounds like normal and the external coils get hot, as expected. So I assume the compressor is good and the problem is either the relay switch OR the thermostat. How can I narrow that down?

The relay measured at ~45 Ω. One Ytuber says the relay should be 0—1 Ω, so I am tempted to conclude my relay is bad. But I also have little confidence in what Ytubers say on these measurements. I have not yet taken resistence measurements on the thermostat, but when I do I expect the same problem: not knowing if my reading is good. Because user manuals withold this info.

I thought perhaps the relay is cheap enough to experiment, particularly in my case because apparently there is no starter capacitor. It’s a quite simple design. The parts shops all say the relay is discontinued, except one, who says they can get ½ a relay (it’s missing a circular part that looks like it might be the part that switches off when hot – not sure). They want €40 for ½ a relay. Fuck me. Not worth the risk. It might be the wrong half, or my problem might be the thermostat (which is also likely unavailable).

But I have to ask, isn’t it foolish that relays are not standardized? Or is there a chance that I can hack together another relay to work? Or do generic relays exist to save these big boxes from landfills?

I could rig up a switch and a pushbutton to turn on the fridge… then off, periodically, but that manual effort will test my tolerance.