The refrigerator does not seem to be very cold, my husband thinks it is because we have so much in it, and I don't think that should matter. I have moved the control up to the coldest point, and it is still not cold. I thought that maybe it could be due to the fact that we haven't cleaned the dust from it in a very long time, probably five years.

Hi,

There are several reasons for the fridge not getting cold. The condenser coils could be blocked with dust, the condenser fan could be bad or stuck, the freezer fan could be stuck or bad, the freezer coils could be blocked with frost because the self defrost system is not working or the compressor is not running because of a bad relay. The list can go on and on. Without specifics one could write a mini service manual that would cover all manufacturer's units and waste everyone's time.
Also would suggest other troubleshooting steps:

The first thing to understand is that all the cooling in a conventional frost free refrigerator usually originates in the freezer compartment, just a small portion of that air is circulated through the fridge compartment to cool there. (Technically the opposite is true. Warm air is circulated into the freezer compartment where its heat is removed by the refrigeration process leaving behind cooled air.) In any case, if that air flow is hampered in any way, cooling problems will result.
The second thing you need to know is that the compressor (large black dome at the rear of the refrigerator) provides all the cooling ability for the whole appliance. It has to be running in order for any cooling to take place. As long as the compressor is running, the possibilities listed below will need to be checked one at a time. If the compressor is not running or continually trying to start but failing within seconds, clicking and then shutting down, someone will need to look into why. That alone is likely the cause of your cooling problems.
Running But Not Cooling
There are lots of things that can cause cooling problems. One of the most common causes of poor cooling in a frost free refrigerator is a defrost system failure. In such a case one or the other compartment may appear to be keeping proper temperature but that too may change in a short period of time. The fridge compartment's temperature rise is usually (but not always) the first to be noticed.
"Frost" and "Ice"
There is a difference between "frost" (a white, snow-like substance) and "ice" (usually clear and solid). When referring to what is seen during an inspection, please keep this distinction in mind as the possible causes for each are often very different.
The Defrost System
Inspecting the (usually rear) wall of the freezer compartment for a frost build up is necessary. (In the case of many GE top freezer models, check the freezer's bottom panel.) If there is a frost coating on it, it is often a sign of excessive frosting beneath it. Sometimes however the evaporator cover panel will actually need to be removed (see the illustration below) before an excessive frost build will visible.



Thank You