[kennysfolly]

evap core freezing up evap fan not working removed and check out ok defrost heater ck. ok defrost thermo ck. ok any ideas? defrost timer? or what else? loosing food and mind, help please

[Jagsmaned]

Hello,

On this unit there would be a possibility that the defrost is defective when the unit is frosting up. Normally for a frosting up issue the defrost timer would not go into the defrost cycle if it is faulty but the fan would continue to run. It is more for the issue to be the defrost thermostat since the evaporator fan relies on it to operate. The evaporator fan will not start until the defrost thermostat reaches a certain temperature. Recheck your defrost thermostat to make sure that it is not separating.

[denman]

First remove the evaporator cover in the freezer so you can see the coils.
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.
On this unit I think the timer is behind the front kick plate.
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.
Best way to test this is a live test to see if you have 120 volts across the heater/defrost thermostat combo.