Fridge is not cold

Side by side cooling units usually have 2 compressors, one for the freezer and one for the refrigerator. The refrigerator compressor may be bad, or not pulling enough power, or there may have been a leak in the tubing that the compressor uses to cool the unit with. To diagnose the problem, be aware of the noises the unit makes, and check to make sure it is a 2 compressor unit. If you only hear one compressor running then your compressor is bad, if you hear one running too often, then your tubing is bad, if the back of the refrigerator side is warm but the inside is not cooling down, then the compressor is not drawing enough power. Keep in mind that the radiant heat from the operational (presumably) freezer side may cause the refrigerator side to appear warm. (usually there is a type of wire backing with tubes running along it, these tubes should be mildly warm.)