Timer question on Kenmore Fridge

[the5wiseguys]

Model Number: 363.59522994
Brand: Sears Kenmore
Age: More than 10 years

Question on how the timer works. Freezer stopped working. Figured out the defrost heater was broken so I replaced that. In the process of trying to figure out what was wrong, I pulled the panel out that housed the timer so I could test it. I know those things are set to kick on 2 or 3 times a day for maybe 20 minutes or so. That timer has a shaft that is flush with the face of the timer housing. While messing with it to test it, that shaft may have been manually rotated. Would that have messed up the factory preset on it? After I replaced the defrost heater, my freezer started working again. Now it's a month later and it won't get below 33 degrees. I'm wondering if that defrost timer is kicking on all the time now from me messing with it.

[denman]

Question on how the timer works.
Every 6 or 8 hours the timer goes into a defrost cycle that lasts about 30 minutes.
The timer can be wired so that it only advances when the compressor is running so defr4ost in this case will be more than an 8 hour cycle.

While messing with it to test it, that shaft may have been manually rotated. Would that have messed up the factory preset on it?
No. The timer only rotates in one direction and it is OK to do this manually. It could be that it was stuck in a defrost cycle and you forced it out of the cycle but now it is not rotating so you are not getting any defrost.
I'm wondering if that defrost timer is kicking on all the time now from me messing with it.

Below is my standard blurb for this type of problem.
First remove the evaporator cover in the freezer so you can see the coils.
If they are heavily iced/frosted over then it is a defrost problem.
Do not let them de-ice.

If yes.
Manually force a defrost cycle by turning the defrost timer cam till the fans and compressor turn off.
There is usually a hole in the cover to let you do this without taking anything apart.
Now check the defrost heater to see if it is on.
Be careful you do not want to burn your fingers.
If the heater is on then the timer needs replacing, re: it is probably stalling during it's rotation so is never getting into a defrost cycle.

If not on.
Unplug the unit.
Remove the wire for one side of the heating element from the wiring and measure it for continuity, usually around 20 ohms or so.

If the heater is OK
Remove one wire to the defrost thermostat and measure it, should be 0 ohms when frozen. Note that it opens just above freezing so must be frozen to check it. Also inspect it, if it is bulged at all replace it even if it measures OK.

If both the above are OK then odds are the defrost timer contacts are toast.

[the5wiseguys]

ok, thanks for the quick reply. I'll get to testing all this and report back what I found. thanks again.

[denman]

One thing to note is that if it is a defrost problem (evaporator coils clogged solid with ice/frost) then the compressor will run all the time unless the unit is in a defrost cycle.

If the unit seems to cycle normally but will not reach the freezer set point temperature (usually around 0 to 5 degrees F then it is most likely a control thermostat problem.

[the5wiseguys]

Have now replaced the heater, timer and defrost thermostat. Freezer cools to -6, then warms to 32 after defrosting. Something keeping the compressor from kicking on after the defrost cycle is over?

[denman]

Is this unit inside or outside?

The reason I ask is that the ambient temperature can effect the compressor coming on after a defrost cycle.

[the5wiseguys]

It is outside in a garage, but has been there for a number of years working fine. This all happened in the last couple of months. I also have an upright freezer out there and it works fine. Thx

[denman]

The freezer may work OK because it does not have auto defrost.
But even if it does it is different than a fridge in that the control thermostat is measuring the actual freezer temperature.
Usually about 0 to 5 degrees F so the ambient temperature must be lower than this to hold the compressor off.

A fridge is different in that the control thermostat is measuring the fresh food compartment temperature.
Usually this is around 40 degrees F so if the ambient temperature is much lower than this the compartment does not warm up during defrost.
The compressor then does not come on right after the defrost cycle so the defrost heat is trapped in the freezer side raising it's temperature.

Could be it is a little colder this year?
It may only take a degree or two.

[the5wiseguys]

No, it has actually been warmer this year. Either way I've tested and replaced the heater, timer and thermostat. All replaced parts test good. Freezer will get to -9, then will warm up to 32. What else would I check?

[denman]

Freezer will get to -9, then will warm up to 32

-9 seems way too low. It should be in the 0 to 5 degree F range.

A few things to check:

1. Is the evaporator (freezer) fan on when the compressor is on?

2. What is the fresh food side temperature? It should be around 38 degrees F.

3. Is air circulating into and out of the fresh food side? On this unit it should enter at the fop through a manual baffle and exit through a vent lower down on the side wall between the sections.

4. If possible try to catch it when it is too warm. Then slightly adjust the control thermostat. Do not go to Off. If the compressor kick on then odds are it is a sticking thermostat.