Manual for defrost timer model# T000067709 a defferent timer was installed ,but now installing the right one need know the wiring for new timer

most of these freezers have an automatic defrost cycle.
after so many hours of chilling it will stop and run a de-icing cycle.
this is accomplished by one or two heating elements.
if one of the elements is burned out it will not run the defrost cycle.
and will ice up quickly.
depending on the model the heaters will usually cost about 15 to 20 dollars and they are easy to replace.
look up the model of your freezer and download the pdf files they will usually have a pictorial diagram showing the location
a defrost timer usually does nt fail on them unless it is physically damaged.

That 8141-00B is a Paragon timer model number. If you get the identical one you can just mark the numbers down and be sure to wire in the new one the same way.

I have a generic wiring diagram that I use on all my installs that works very well. It is basically the same for most all commercial walk in freezers. Send me a email address and I'll scan and forward what I have.

Click Here for your user manual=> MQU1556AEW.pdf The settings for defrost should come automatically every 12 hours. You may test the defrost timer that appears to be behind the kick plate at base and front bottom of refrigerator by removing the kick plate first and using a flathead screwdriver turn slowly clockwise until compressor stops. After a few minutes you should be able to hear a crackling noise or sizzle by opening the door and listening. Leave the timer like that for up to 35 minutes and if the freezer does not start on its own the the timer is not working properly and will need replaced. Click Here=> MQU1556AEW Unit parts number 15 in photo is defrost timer. The defrost timer is part number=> 4357124 Defrost Timer Check for air leaks around door seal as this will cause the same symptoms. If by chance the defrost timer works and the defrost does not then let me know here or here=> Appliance 911 The only other parts are the defrost heater number 16 in photo MQU1556AEW Unit Parts and part number for defrost heater is Click Here=> 8201749 If you change the defrost heater it is always good to replace the defrost thermostat number 18 in MQU1556AEW Unit Parts The defrost thermostat is part number=> 1-81801-001 The most likely problem is the defrost timer but I needed to cover every possibility. If you have questions please feel free to ask, Thanks, Sea Breeze

Hi Guys, I tested fan removed(to 240vlts) neg- pos to wires+earth to mount bracket, and found to be working, reinstalled and found power - active to both wires??fan cut out (defrost mode)activated by timer control, my timer control ( bottom rear near motor) has a knob, so i turned it and fan started,continous turning knob ran thru all cycles defrost,fan start, etc: obviously timer control was faulty, To save frozen goods , i set control to run and installed a power point timer to cycle freezer till new switch arrives, taking the place of faulty controller...

The evaporator coil behind the cover on the back wall inside the freezer will ice up under normal conditions. Every 8 to 10 hours for around 20 minutes the defrost timer (or in most newer models the electronic adaptive defrost control) will turn the defrost heater on to melt the built up ice. There is a defrost thermostat which prevents the heater from overheating the freezer by breaking the heater circuit when the temp reaches close to 32 degrees F. The entire cooling system shuts off during the defrost cycle and starts back when the timer advances through the cycle.

If this ice is not melted it will continue to build up until the air can’t flow over the coil to circulate the cold air through the freezer and into the fridge. The temperature change in the fridge is usually noticed first followed by the freezer.

If the defrost thermostat is bad it can prevent the heater from coming on OR it won’t turn the heater off when it gets too warm. It is clamped to the evaporator coil at the top to sense the temp. If it appears to be misshapen it is bad.
With an ohm meter it should show continuity when cold and none when warm.
You can also bypass the thermostat to see if the heater comes on then. If it does then you know the thermostat is bad and needs replaced.

The defrost heater is located on the evaporator. It is in a tube which is at the bottom and can also go up the sides of the evaporator. On some types you can see a burnt spot if it’s bad. With an ohm meter it should show continuity from end to end when disconnected from the wiring in the freezer. You can also test the wiring for voltage when it’s in the defrost mode.

If you have a defrost timer you can test it. It can be located under the fridge behind the kick panel on the front. Some are in the fridge with the controls at the top. You can turn the defrost timer till it clicks and everything shuts down. The heater should now come on. If it does, replace the timer because that means the timer is not running. If it doesn't, check the heater and defrost thermostat. Turn the timer again till everything starts back up to end the defrost cycle.

If you have an adaptive defrost control instead of a timer, replace it if the heater and thermostat test good. It is located in the fridge with the controls in some models and on the back in others.

If you need help finding your model number see here> http://www.appliancepartspros.com/modelnumber_locator.aspx

To locate your timer, motherboard, control or adaptive defrost control , enter your model number and search for the part or post back on Fixya.
http://www.searspartsdirect.com/partsdirect/index.action?psid=26129238&sid=PSx20071217x00001a

you might have a defrost problem. Frost free models have a heating element that is controlled by a timer to automatically defrost ice, defrost timer turns on defrost heating element every 12 hours to melt ice in freezer and allow good air flow.
You can test defrost element with an ohm meter(located inside freezer coils-will have two wires going to a plug connection), if OK replace defrost timer (located in various places depending on make and model

The reason this happens is because the defrost timer is not turning back on when it needs to, causing the freezer to thou out and overfill the drip tray sitting on top of the compressor. A new defrost timer should be available from the local refrigeration wholesalers in your area.

I just turned it off and pulled out the super defrost button. I used towels not the drainage plug since I couldn't find a pan of any sort.

Also...very funny comment about my husband taking care of it!

Most likely you have a defrost problem. IF, you think the timer is ok then the most likely problem is the bi-metal. That is a little part usually on the top right side of the evap coil and has two wires on it. If you can find the defrost timer and advance it slowly till the refrigerator stops running, then being in the defrost postion you can see if the heater is coming on. If so you have a bad timer. If NOT, then either the heater or the bi-metal is bad. Usually it is the bi-metal