Kitchen Large Electric Appliances - defrost problem

I have a Frigidaire crown series side by side upright refrigerator model F45WJ26H, my problem is the freezer coil arefreezing up to a block of ice and preventing the fan from circulating the air, I have to shut it down for a couple hours and using a hair dryer to deice the coils, then turn back on and it last for about 3 to 4 days and I have to do it again. I have replaced the thermostat in the freezer section already and the chiller side therm. appears to be fine. I suspect the defrost system is the problem, but I am not sure how the defrost works in order to troubleshoot. Is there anyone who can explain how it should work and how to go about troubleshooting it. any and all help would greatly appreciated.

Does this model have a defrost timer? Often located either with the thermostat control inside, or under the machine behind the toekick, or at rear. If you have one of these, it be a rectangular box. They also have a small dial on them that you can use either your finger, coin or an instrument of some sort, to turn the dial. They are made to turn only one direction and to prevent reversal they have sloped edges where you turn it, so it can go only the way intended. Observe where the slot is aiming. Put mark on fridge if need be and make sure it moves on it's own over time. If yes, turn off all breakers in the house except the one for the fridge. Then advance the timer dial until it clicks. Then go outside and look at your electric meter to see if it spins (if you have the old dial-type electric meter). I own a Kill-A-Watt plug in volt-amp-watt meter to check it. [You plug one of these into your fridge outlet as you would a lamp timer (they look quite similar), and then plug your fridge cord into the test meter, and push the watts button. It would read in the neighborhood of about 450 watts if the defrost element is allowing current through it while in defrost mode. If it does not, and you try rotating the defrost dial again, slowly waiting for the click, to be sure you are in defrost mode, then you have some electrical breakdown, either with the defrost timer, the defrost thermostat, or defrost element, all of which can be tested.

[If you have a newer digital controlled fridge, they may employ some other components that I believe Himeros is more familiar with.]

Model number search shows it to be make in 1996, it uses a manual defrost timer. The defrost timer could be almost anywhere, behind the toe kick, behind the refrigerator, or most likely, at the top of the refrigerator section. You can tell from how it is mounted, there will be two small, about #6 screws holding it in place, and almost in the middle of those screws will be an opening, about 1/4 inch. Inside that hole will be the shaft you need to turn, I use a small pocket knife to do this. The best way to do this is turn the cold control to shut the refrigerator off, turn the timer knob untill it makes the first louder click. If you go too far, it will make the second louder click. Once you master stopping at the right spot, turn the refrigerator back on and check if the heaters come on. One note to go with this, the refrigerator must be on and running before starting this procedure to check the defrost circuit. A good investment would be a cheap meter so you could check the heater coil, and other parts.
H.

I will ckeck this out thanks for the info. I will let you know what I find.

I found the defrost timer like you said in the kick panel. I rotated it clockwise until it clicked loud and obresved the coils and no defrosting took place, then shut the frig down and cut the wires to the thermostat, then I put my volt meter on the cut wires. turned on the frig and rotated the timer until it clicked while observing the meter and noticed I had power as soon as it clicked. so I shut the frig off again and hooked up the wires again bypassing the thermostat and turned on the frig and it started to derost immediately. so it was the thermostat alright, now can I leave the thermostat bypassed temporarily until I get the new thermostat? will it cause anymore problems, I'm talking only a couple of days until places open up after the holidays? thanx for the assist.

You can do that, but the defrost heater will stay on longer than when you have the limit switch installed. The way this works is the timers are different time in defrost cycle, but usually about 25 minutes. The defrost limit switch you need will cut off the heater when the temp in the freezer rises to the temp of that limit switch, which can be around 40 F. The timer now will keep the heater turned on for the total time of the timer defrost mode. The only problem will be that the freezer will warm up more than it should, Just load that freezer section up will gallons of water or ice packs to keep the temp from rising too much. Good find, saved yourself many dollars, probably $80.00 or more.

H.

I will do that, I should be able to get it on moday and put it in the way it's supose to work.

The freezer coil was iced over when you checked the defrost thermostat? Right? If not, the stat may have been open due to it's temperature being above the temperature it opens at.

:confused: Why would anyone tell someone that it is okay to leave the defrost thermostat by-passed. The heaters will stay on and the fan motor will not run.
This thermostat is dual purpose. 1. To terminate defrost. 2. To delay the fan from starting until the coil temperatures are at the proper level. This prevents blowing warm air around after defrost.

Best to leave the terminator wires loose till you get the item.