My side by side freezer is working fridge wont get cold,compressor is working.

There is a panel, or door if you will, that separates the freezer and fresh food compartments. The freezer temp control determines how much cold air is allowed to escape into the fresh food compartment by opening or closing this panel.

If the panel is restricted from moving (stuck closed, for example), the freezer will get VERY cold while the fresh food compartment will be warm.

Try thoroughly defrosting the refrigerator. Possibly an accumulation of ice is preventing the panel from moving and/or is restricting air flow from the freezer to the fresh food compartment. It's a free fix and may solve your problem altogether.

If that doesn't help, or helps only temporarily, you may have a problem with panel itself or the linkage that connects it to the control mechanism. Unless you're skilled in appliance repair, checking and repairing these components will require a service technician to check and repair these components.

Hope this was helpful. Good Luck.