How do you get it working to a cold tempreture and set it ?

Bad air door actuator or something as simple as a vacuum leak or bad vacuum check valve.

Nominal tempreture for your refrigerator is 36-38. on the Freezer the tmpreture should be between 0-2. One of the first things to check is on the freezer side is there any frost or snow build up on the rear wall of the freezer. If there were this is termed as a defrost issue. If you do have this issue with frost build up message me back and I will instruct you how to repair this issue. Another thing to check is if the evaporator fan inside the freezer is blowing the cold air into the refrigerator. The Freezer section is the only area that produces the cold tempreture a fan blows the cold air off the evaporator coils through a damper door that opens and closes depending on the tempreture the refrigerator side is set to. Also check the damper door for any ice build up as well this would cause the door not to open and close and remain in a stuck postion. This would cause inadequate tempreture in the refrigerator side as well. If you have any questions or need any schematics or step by step instructions message me back the model number of your unit and I will provide these and answer any further questions you may have. I await your reply
Thank you
Rick

Nominal tempretures for the refrigerator side are 36-38 degrees. Nominalk tempreture for the freezer section is 0-4 degrees. Your main board that controls your entire refrigeration can be found on this diagram as 1-5 http://c.searspartsdirect.com/lis_png/PLDM/50039314-00004.png
What tempreture are you trying to achieve? By setting the unit colder you also cause the unit to work harder as well shortening the lifespan of your refrigeration compressor as well as other key parts that perform to make your unit produce cold. Some key things to look for are any type of freeze up on the rear wall of the freezer which is termed as a defrost issue and if you do have this issue message me back and I can instruct you to solve this situation. I await your reply
Thank you,
Rick

on any refrigerator or freezer it should be set in the middle whereas if your unit said 0-9 you would set your unit to 5 or if it just says min and max in between these would be the the best. optimum tempretures are at 37-38 in your refrigerator and 0 in your freezer if you have any further questions message me back and please remember to rank how this opinion has helped it allows for me to help others in similar situations Thanks Rick
p.s it is also best to keep two manual thermometers in both the freezer and the refrigerator at all times this way you always know your exact tempreture

try setting your refrigerator to a medium tempreture as it's getting cold so it will be good if you set it between low and medium somewhere you need to change the tempreture setting according to the cliamate even if the refrigerator is frost free .well it certainly does not mean that there will be no frost formation even if you keep it operational at high cooling inside

the ideal temperature of a fridge is +2c and for a freezer -18c so leave it alone.where it is.

try turning the blower down, if you have the fan on full you will feel cooler air from time to time. as the thermostat only measures the ambient tempreture inside the car when this level is met then it will turn off the heat so it will only blow the air from the car which will feel cooler.
if the car is still cold suspect the tempreture control in the car maybe faulty or the water level in the system maybe low.

suspect tempreture sensor on drivers side. it seems to send a signal that this side of the car is too cold.

if you have duel setting so driver can control both sides at same time set also to air and see if it jumps to heat on both sides, if so there seems to be an electical problem with the tempreture contoler.

is the heater blowing hot or cold ?
if its cold your thermostat could be stuck open, and the engine wont warm up

it sounds like a bad thermostate, it culd be easier and cheaper to get a new heater. Check their website for replacement parts and be sure it's a job you think you can tackle.