My may tag fridge GS2126PADB seems to run fine but the freezer is not blowing cold air and fridge & freezer are warm.

Rachael, I recently had a similar issue. Unfortunately, the problem you describe could be related to several components & sensors that could have failed which cause similar symptoms. There are a few things that you will need to start with in order to best lead you in the best direction for repair. First, ice building up says that there may be a problem with the auto defrost cycle. Usually a sensor that sits on the evaporator in the freezer side. You want to start with actually measuring the temp in the freezer and the fridge. If you can, remove items, turn fridge off & then unplug fridge from outlet. Let sit overnight with doors open. Two goals, here. One, ensuring that any ice that has formed in the air passages has a chance to melt completely. Second, unplugging the fridge helps "reset" the control module. You stated "hearing the motor" working. Do you mean the compressor or the fan in the fridge. IMPORTANT, you need to make sure that when the fridge is "running" that you can feel air blowing in the freezer & fridge section. Do this before turning off & unplugging. Lastly for now, did anything out of the ordinary happen before you noticed improper operation?

Sounds like one or more of ofvyour 3 defrost components have failed which are defrost heater , defrost thermostat, and defrost timer or board

all it does is blow cold air from the freezer into the fridge section,open the freezer door,you should hear the fan blowing,no fan fridge will be warm bad evap fan motor,also send the brand name and model number,some machines have dampers in them if the damper is bad it blocks the cold air from entering the fridge section,send model number and brand name,

send the model number off of the fridge,if the freezer is working fine then no air is being blown up to the fridge section,all it does is blow cold air from the freezer to the fridge section so either the door was left open and this is very common with a bottom mount freezer or the evap fan isn't blowing or on some models there's a damper inside the fridge section,the damper door opens and closes to let cold air in,when it reaches temp. the door closes,sometimes the door gets stuck in the closed position or the open position and the fridge freezes or gets warm depending on where the door is.first thing open the freezer door,do you hear the fan blowing,if not you could have a bad evap. fan motor,next look at the ceiling and on the packages,do you see frozen water droplets,if so the door was left open and the air ducts are froze up from the warm air getting in from the door being open and mixing with the cold air freezes up the air ducts,also stick your hand onto the back inside wall of the freezer,if there's like snow or frost on the inside back wall of the freezer you could have a defrost problem,bad defrost thermostat,heater,timer or board depending on the model or last a bad damper,when you open the fridge door there are air ducts usually up top and in the middle you should feel cold air blowing in,this is your problem the air isn't making it into the fridge section.if the door was left open,unplug the fridge,remove the food from the freezer and with a hair dryer heat up the back inside wall of the freezer and blow the hot air into the air vent holes in the back wall to melt out the air ducts,keep heating it up until you don't see any more water dripping,you can see the water dripping through the vent holes.so let me know what you find,send the model number and we can go from there.look up near the ceiling in the fridge section on the right hand wall and you should see a tag with the model and serial numbers,send the full model number so i can see what you have in your machine.

open your freezer and see if it's blowing cold air,or if it's just cold,if it's not blowing cold air it's probably the fan, u will find this right behind the vents in the freezer,remove vent in freezer there should be a fan if not running replace this should resolve your problem

Two thoughts. If the fan is running... and you can here it in the freezer when it is on. Then the fan is fine and it is the mixer control. IF the fan is not working, then fix the fan.

The mixer control is in the top of the fridge where the air comes out on the wall between the fridge and freezer.

I think maytag calls this a cold control / damper.

Basically it controls the air flow rate between the fridge and freezer. When it is opens it allows air from the freezer into the fridge and cools it off.

Hope this helps.

The fridge gets its cold air from the freezer through a vent(damper) between the freezer and fridge.The fan in the freezer blows air through it. Make sure this fan is running. You may have to hold the door switch in for it to run. There is a flap you adjust with the fridge temp. control. Make sure it's opening and closing when you adjust the fridge temp.
The problem could be the electronic control if you have one or the mechanical linkages.

If the evaporator coils behind the back panel of the freezer are icing up because of auto defrost failure that will stop the circulation of cold air and eventually affect the freezer too.

check defrost timer, defrost heater, defrost thermostat. In most newer models the timer has been replaced by an electronic control board. If the heater and thermostat are ok it’ll be the control.

sounds like compressor has failed remove the fridge and put your hand on the black unit at the back (compressor) it should be quite warm if running if not its not starting compressor are at there most stress when starting up and if failing this defrost may have killed it completely

"it seems to work fine but will not get cold"
Not sure how it can work fine and is not cold. When you say work fine, is the light on and the freezer fan blowing but is the compressor running?

Unplug the Ref and wait about 30 min or so, plug it back in and listen for the compressor to start running. You should be behind the Ref to hear this. If you don't hear it start running then you may hear a clicking noise. This clicking is a problen with the compressor start relay. If the compressor runs but still is not cold then it could be low on coolant.