Not cooling either side. compressor not running

Check its thermostat whether or not its working ok. Otherwise the compressor could be out of order.

2 possible issues. If compressor running, but not cooling - No freon in the system, or compressor valves are bad, not compressing freon. Ideal would be to check pressures on the system while its running. Could be some kind of restriction. most common problem i would guess low freon level. Here are 2 of my videos i have on my channel. first is leak found at evaporator coils. i used leak dye to find it, second video is replacing compressor, but had compressor completely down. installed 3-n-1 hard start kit, but compressor did not come on, so replaced compressor with filter drier. Hope this will give you an idea what to do next.

If the compressor is running almost all the time (and the compressor sounds ok - no pinging/clunking),
then your side-by-side has developed a coolant leak.

When a system is low on coolant, the thermostat detects the warm condition of the refrigerator, and
runs the compresor motor in an attempt to cool off the refrigerator compartment, but if there's little
or no refrigerant in the system, the system's attempt to cool off the refregerator/freezer will fail,
with the symptom that the user wil hear the compressor motor running constantly.

1.The fan motor at the compressor must be running to keep the compressor cool.2. If you hear a clicking sound at the compressor,that is a indication of a bad compressor start relay that must be replaced.

Check your compressor relay- http://www.acmehowto.com/howto/appliance/refrigerator/check/compressorrelay.php

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.)

When the fans are running the compressor should also be running. If the compressor is hot but not running you have a compressor problem. If the compressor is running check for frost on back wall of the freezer compartment which would indicate a defrost system problem. At five years old have you cleaned the condenser where the heat is transferred to the outside air in the room?

hi thanks for the question is the compressor running hot if its not hot and the fan by the compressor is running the problem is that the compressor is not starting check the compressor you might need a new start relay mounted on the compressor thanks the appliance doc

hi thanks for the question you say the fridge is still running is the fan in the freezer running at the back is the compressor running if the compressor is not running and is very hot it could be a bad compressor is there a fan down by the compressor if there is a fan by the compressor is it going if not replace the fanthanks the appliance doc

Cleaning the fins is always good. Is the fan by the compressor running? It needs to help cool the compressor. The description you mention sounds like the compressor is overheated and tripping the thermal overload on the compressor. See if you can turn if off for a day to let it all return to room temp then see if the compressor kicks on. If it was overheated it should run again for a while before overheating again. Let us know how that works and we can go from there.