Freezer compartment getting warm especially at the top. I took the back panel off of the freezer and removed the Heating Element and initially it reads 0 ohms and then within a second or two the resistance goes up to 28 ohms. When I start the refrig the evaporator fan at the top part of the freezer comes on slowly and then comes up to speed and moves a lot of air. I’m not sure where the heating element thermostat is located (it may be clipped to the top of thye condenser coil). I haven’t checked that. I also an assuming that the defrost timer function has been taken over by the main control board (AP4436216). Is that true? Is it possible that we have overloaded the freezer limiting the circulation of cold air?
Dhs,
Based on your post, You have a cracked defrost heater( 0 ohms then 28 ohms) Presuming you tested the heater with the wires off at the terminals.
(always remove at least one wire off the component,when testing resistance, so you don’t get a false reading).
You’re corect, the defrost hi limit thermostat is mounted(clipped) onto the top of the evaporator tubing. It should have a closed circuit across the two wires at or below room temperature.
The defrost system is controlled through the “mother board” based on inputs from various components in the system. That’s not where you want to start, after you recheck or replace the heater and thermostat, would be the time to consider it.
By the way, you have your terminology wrong, the Evaporator Coil is in the freezer compartment, your Condenser Coil is located in the compressor compartment, in the back of the refrigerator. You should consider, checking and cleaning the condenser coil, if you haven’t yet.
Thank You for your response. You’re right I was referring to the evaporator coil. I tested the defrost heating element with both leads removed. When I test the Defrost Limiter Thermostat should I read zero ohms when the thermostat is at zero degrees and an open circuit when the thermostat is at room temperature.
As long as the rear of the freezer is open does it make sense to replace both the thermostat and the defrost heater? And, I did clean the condenser coil which was an embarassment..
Should I be concerned that the evaporator fan seems to start slow and then builds speed after about 5-10 seconds??
Thanks again.
[quote=dhs70flh;400634]Thank You for your response. You’re right I was referring to the evaporator coil. I tested the defrost heating element with both leads removed. When I test the Defrost Limiter Thermostat should I read zero ohms when the thermostat is at zero degrees and an open circuit when the thermostat is at room temperature.
As long as the rear of the freezer is open does it make sense to replace both the thermostat and the defrost heater? And, I did clean the condenser coil which was an embarassment..
Should I be concerned that the evaporator fan seems to start slow and then builds speed after about 5-10 seconds??
Thanks again.[/quote]
DHS,
Don’t worry about the condenser coil, just remember to check and clean it every couple of years, it makes the fridge more efficient, as a matter of fact I need to clean the one on my fridge…
As for the thermostat repalcement, I usually replace both,but I was leaving that up to you, it’s a good idea,though.
Your evaporator fan, is a variable speed fan, they usually start out on the low speed, then step up to the high speed, Your fan is OK, based on your description.
I’m pretty sure you’ll be fine,from heere on out.
Thank You again for your help. Parts are on order from you guys. Just waiting now.
Great,
Drop us a line, and let us know how things worked out.
I replaced the defrost heater and the defrost hi limit thermostat. Everything was fine for about 2 1/2 weeks, then the same problem again - evaporator coil completely iced up. Assuming that the parts I got are good and I installed them properly, it seems that we still have the same problem. I tested the new defrost heater before I installed it and was a little concerned when I got the same resistance readings on the new defrost heater that I did on the old one, but I put the new parts in anyway.
What now? It would seem now that the problem is either the main control board or internal wiring. Have any suggestions as to where to go from here other than buy a new non-GE refrigerator??
[quote=dhs70flh;420302]I replaced the defrost heater and the defrost hi limit thermostat. Everything was fine for about 2 1/2 weeks, then the same problem again - evaporator coil completely iced up. Assuming that the parts I got are good and I installed them properly, it seems that we still have the same problem. I tested the new defrost heater before I installed it and was a little concerned when I got the same resistance readings on the new defrost heater that I did on the old one, but I put the new parts in anyway.
What now? It would seem now that the problem is either the main control board or internal wiring. Have any suggestions as to where to go from here other than buy a new non-GE refrigerator??
[/quote]
DHS,
Here’s a quick test procedure for the “motherboard”. It’ll help determine where the problem is. You’ll need a short piece of wire with both ends stripped of the insulation(jumper wire).
With the refrigerator running, unplug it and remove the motherboard cover in the back.On the mother board locate the power connector in the bottom, left. Pull the connector off the motherboard and put a wire jumper between the connector pins of the wire harness that mate with the motherboard pins labeled line and def. Plug in fridge.
If you now get defrost action in the freezer, you motherboard is probably bad.
If no defrost, you have either a bad defrost heater, defrost thermostat,or wiring problem.
In this way, you will be able to confirm which parts are bad.
Just in case,
Good Luck,
I had defrosted the evaporator coil and now the refrigerator has been running again for about a day. I’m assuming the defrost hi limit thermostat will be set properly for this test when the freezer temp is cold. Is a 16 ga. jumper wire heavy enough? And I’m assuming the jumper wire is connected to the plug that was disconnected from the circuit board.
How do I know if the thing goes into defrost cycle? Is it something I can see by looking or feeling at the defrost heater?
[quote=dhs70flh;421169]I had defrosted the evaporator coil and now the refrigerator has been running again for about a day. I’m assuming the defrost hi limit thermostat will be set properly for this test when the freezer temp is cold. Is a 16 ga. jumper wire heavy enough? And I’m assuming the jumper wire is connected to the plug that was disconnected from the circuit board.
How do I know if the thing goes into defrost cycle? Is it something I can see by looking or feeling at the defrost heater?[/quote]
DHS,
Correct on all counts, the thermostat/ thermistor, has to be a closed circuit(evaporator area needs to be 35 to 45 degrees(usually). It’s probably cold enough by now.
A 16 guage wire, should be heavy enough for a jumper wire, and yes, you’ll install the jumper wire in the connector/wire harness, not on the board.
Usually, you can hear or feel the defrost cycle. Quite often, and after a few minutes that the heater is on, you can hear the defrost water “sizzle” when it drips down on the heater, you can visually see the heater glow red, and if your careful, you can feel the heat, by putting your hand near the element, Carefully.
I removed the cover on the motherboard and didn’t find any connector in the bottom left corner. And looking over the motherboard didn’t find any connector with the designation of ‘line’ and/or ‘def’. Everything seems to be designated with ‘Jxx’ numbers. There is a heavy duty connector in the bottom center of the board with designations of ‘J8’, ‘J9’, and ‘J11’ (left to right). However, the colors on the plug wires don’t correspond with the colors of the wires on the defrost heater. I’m at a loss. If it helps the motherboard has designations of ‘WKKT 1304-00-00’ and ‘200D6221G009’ - don’t know if those are part numbers or not.
Multi-connector plugs across the top are labeled ‘J1’ thru ‘J4’. There’s another multi-connector plug at the bottom (next to the heavy duty plug) without designation (has pretty heavy wiring).
Please help if you can…
[quote=dhs70flh;421449] I removed the cover on the motherboard and didn’t find any connector in the bottom left corner. And looking over the motherboard didn’t find any connector with the designation of ‘line’ and/or ‘def’. Everything seems to be designated with ‘Jxx’ numbers. There is a heavy duty connector in the bottom center of the board with designations of ‘J8’, ‘J9’, and ‘J11’ (left to right). However, the colors on the plug wires don’t correspond with the colors of the wires on the defrost heater. I’m at a loss. If it helps the motherboard has designations of ‘WKKT 1304-00-00’ and ‘200D6221G009’ - don’t know if those are part numbers or not.
Multi-connector plugs across the top are labeled ‘J1’ thru ‘J4’. There’s another multi-connector plug at the bottom (next to the heavy duty plug) without designation (has pretty heavy wiring).
Please help if you can…[/quote]
DHS,
Your defrost heater circuit is the J9 connector, on he left side, mid way, of the motherboard.
Do the same process as before, jump the wires, plug the cord in and give it a minute or so, then check the heater.
Joe, I Hate to appear denser than I am, but I still have a question. I think my problem has been that you have been talking about the motherboard looking at it from a horizontal aspect as pictured in the parts picture (J8, J9, & J11 on the left side). In the refrigerator it is mounted in a vertical position with the Jxx located on the bottom. So much as to why I was confused.
My question is which pin represents ‘line’, my guess is it’s ‘J11’, but I want to be sure. I think the jumper should be between ‘J11’ and ‘J9’. Correct??? Thankyou in advance.
[quote=dhs70flh;423208] Joe, I Hate to appear denser than I am, but I still have a question. I think my problem has been that you have been talking about the motherboard looking at it from a horizontal aspect as pictured in the parts picture (J8, J9, & J11 on the left side). In the refrigerator it is mounted in a vertical position with the Jxx located on the bottom. So much as to why I was confused.
My question is which pin represents ‘line’, my guess is it’s ‘J11’, but I want to be sure. I think the jumper should be between ‘J11’ and ‘J9’. Correct??? Thankyou in advance. :)[/quote]
DHS,
Almost,
Try this check for voltage,on the board,
J9 Blue Defrost heater Output J9 to J7 pin 9 = 120 VAC, then jump the J11pin 1 to J9pin 1
Lets see what happens.
Joe, The measurement across J9 and pin 9 of J4 didn’t read 120v (assuming that the pins are numbered from left to right looking at the top side of the motherboard). Instead - 1.4 mV with J4 plugged into the
motherboard
- 1.4 mv with J4 unplugged measuring
pin 9 of the plug - 1.1 V with J4 unplugged measuring
pin 9 on the motherboard
In addition, I jumpered J9 and J11 with it disconnected from the motherboard and the defrost heater glowed bright read within a minute.
Bad motherboard???
[quote=dhs70flh;423984]Joe, The measurement across J9 and pin 9 of J4 didn’t read 120v (assuming that the pins are numbered from left to right looking at the top side of the motherboard). Instead - 1.4 mV with J4 plugged into the
motherboard
- 1.4 mv with J4 unplugged measuring
pin 9 of the plug - 1.1 V with J4 unplugged measuring
pin 9 on the motherboard
In addition, I jumpered J9 and J11 with it disconnected from the motherboard and the defrost heater glowed bright read within a minute.
Bad motherboard???[/quote]
DHS,
Yes, bad “Motherboard”, But now we’re sure.
Sorry it took as long as it did, and thanks for the extra effort.
Joe, Thanks for your help. It’s been a pleasure working with you. Thanks again. I’m going to order the part now.
Dhs,
It was my pleasure, working with you.
Let us know when you’re up and running, we’d appreciate it.
Evaporator coil still frosting without a defrost. After ordering new mother board I manually defrosted the evaporator coil intending to use the refrig until the mother board showed up. As it worked out the refrig started running defrost cycles for at least three cycles that I know of. But, after about 4 weeks it ceased defrosting. I then went with the new mother board. In doing that I jumpered the plug between (DEFR & LINE) to insure that the defrost heater and defrost hi limit thermostat were still OK. When the jumper was in place on the plug and the refrig plugged in, the defrost heater glowed red and seems OK.
So, I replaced the mother board. After doing so it went thru several defrost cycles and seemed OK. But, again after about 2 or 3 weeks the evaporator coil frosted completely again. Again manually defrosted and watched it go thru two defrost cycles (by watching the water catch tray). Once again, it ceased defrosting. I thought that the earth ground wire looked a little inadequate so I wired a supplement wire to the chassis to insure the earth ground on the mother board is good. But, once again it went thru a couple of defrost cycles and then quit defrosting.
I’m at a loss - do you have any suggestions? I don’t know what triggers the defrost cycle but it seems that whatever the trigger, it doesn’t seem to think it needs to defrost (too bad it’s not a timer like in the old days). Thank god I have a 20 year old refrig in the garage to fall back on when the 4 year old one craps out.
[quote=dhs70flh;479886]Evaporator coil still frosting without a defrost. After ordering new mother board I manually defrosted the evaporator coil intending to use the refrig until the mother board showed up. As it worked out the refrig started running defrost cycles for at least three cycles that I know of. But, after about 4 weeks it ceased defrosting. I then went with the new mother board. In doing that I jumpered the plug between (DEFR & LINE) to insure that the defrost heater and defrost hi limit thermostat were still OK. When the jumper was in place on the plug and the refrig plugged in, the defrost heater glowed red and seems OK.
So, I replaced the mother board. After doing so it went thru several defrost cycles and seemed OK. But, again after about 2 or 3 weeks the evaporator coil frosted completely again. Again manually defrosted and watched it go thru two defrost cycles (by watching the water catch tray). Once again, it ceased defrosting. I thought that the earth ground wire looked a little inadequate so I wired a supplement wire to the chassis to insure the earth ground on the mother board is good. But, once again it went thru a couple of defrost cycles and then quit defrosting.
I’m at a loss - do you have any suggestions? I don’t know what triggers the defrost cycle but it seems that whatever the trigger, it doesn’t seem to think it needs to defrost (too bad it’s not a timer like in the old days). Thank god I have a 20 year old refrig in the garage to fall back on when the 4 year old one craps out.[/quote]
Dhs,
I’m at a loss as well, nothing makes sense at this point.
Your defrost cycle is controlled through the “new” motherboard, by the inputs from the door switches and thermistors, etc.
[FONT=Arial-BoldMT][SIZE=3][COLOR=#231f20][FONT=Arial-BoldMT][SIZE=3][COLOR=#231f20][FONT=Arial-BoldMT][SIZE=3][COLOR=#231f20][LEFT]"Freezer Defrost Cycle[/LEFT]
[/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][/COLOR][/SIZE][/FONT][FONT=ArialMT][SIZE=3][COLOR=#231f20][FONT=ArialMT][SIZE=3][COLOR=#231f20][FONT=ArialMT][SIZE=3][COLOR=#231f20][LEFT]The freezer evaporator utilizes a defrost heater to remove frost from the coil. The control board determines the length of time the heater is energized. It does this by monitoring the freezer evaporator thermistor. Once the temperature of the thermistor reaches 75°F, the control cycles the defrost heater off. A bi-metal safety thermostat provides a backup in the event the evaporator thermistor fails. The safety thermostat prevents the temperature from exceeding 140°F."
My best guess, a loose wire or connection at the freezer wiring harness.
You may want to disconnect, dry out all the connectors, and put a coat of vaseline or di electric grease on/in the connector(s) when you re attach them. This will help to keep moisture out of the connection and causing the wires to separate.
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