If it's not the defrost timer....

[Chuck52]

Got an old Frigidaire, maybe 8-9 years old, that quit cooling a few weeks ago. I figured it was something simple, but we wanted/needed a new refrigerator anyway, so I stuck the old one in the basement to wait for me to play with it. When I was checking it out, the first thing I did was manually turn the defrost timer. It started cooling right away, so I replaced what I figured was a faulty timer. It ran for a few days just fine, but it has now stopped cooling again. I think maybe the next likely and fairly easy thing to check is the overheat cutoff on the compressor, assuming there is one. There may also be a bad cap on the compressor motor I suppose. Anything else come to mind?

Chuck

 

[tallyho8]

It could be dirty condensor coils under the refrig or a bad condensor or evaporator fan motor, the compressor overload, the defrost thermostat, defrost heaters, drain heater or thermostat, in that order.

All assuming that the new defrost timer is good and was installed correctly....

 

[Steve_Miller]

It could be dirty condensor coils under the refrig or a bad condensor or evaporator fan motor, the compressor overload, the defrost thermostat, defrost heaters, drain heater or thermostat, in that order.

All assuming that the new defrost timer is good and was installed correctly....

I'll second that about the defrost timer. It was an issue for me several years back. Got a new one and it lasted less than a week. The other thing could be that the defrost coil could be bad and welding your contacts in the timer.


Steve

 

[Chuck52]

Thanks for the input guys. I need to test the compressor contacts to see if the electrical coils are good. If I get proper resistances there, I suspect the PTC starter or the run capacitor attached to it may be bad. The defrost timer is pretty straight forward to replace, and the external coils are clean. It might be one of the other item Tallyho mentioned, but I'm reading lots of problems with the PTC starters. They are cheap solid state replacements for the old standard mechanical relays. The compressor started up after I pulled the starter and capacitor and then plugged them back together. There was no residual charge on the capacitor when I took it off, but that might not mean anything. If the compressor tests OK for resistances, it should be pretty cheap to put on a new starter and capacitor. Easy to get to, too. The fan is working, BTW. I think at least the new timer is also OK, since I can turn the compressor on and off by manually turning the timer. It would be odd for the clock part of the timer to get fried quickly, I would think.

Chuck

 

[Chuck52]

Well, the resistances on the compressor turnings look about right, but I found that one of the three contacts on the compressor electrical plug was rough...looks like it had enough resistance to arc a bit. The corresponding hole in the PTC starter also looks like it got hot. The plastic around the hole looks like it got hot anyway. Neither is badly burned, but it is further evidence that the starter or capacitor may be bad or getting there, I think. I can replace the starter and the cap, probably pretty cheap, but I may need to tin the contact on the compressor to make sure I get good contact between it and the new starter plug. I don't guess there's any better way to fix that degraded pin, is there? It's probably down to 3/4 the original metal on that wire, so it might not make really good contact even with a new starter plug.

Chuck

 

[tallyho8]

What you are describing is that the compressor terminal is burned and that the relay terminal that it plugs into is burned also. You must make sure that the terminal on the compressor is cleaned well and the terminal on the new relay can be smashed together a little to make it fit tight on the compressor terminal.

Many times these terminals get burned when the compressor is pulling too many amps. Usually this is when the condenser coils are dirty and it over heats or when the start capacitor is weak but mostly it is when the compressor is about worn out with bad bearings and is hard to start.

Replacing the relay and start capacitor is cheap enough to do to see how long it lasts. It may possibly last a long time. However, if the terminals burn out again, it is time to scrap it.