You likely have an incompatible control box model. The 9430A751 with dual SIG terminals is designed for true multi-zone systems, while your single-zone setup needs a simpler control box with one SIG terminal.
When your Everchill 12V refrigerator's freezer works but the fridge compartment doesn't cool, it's typically caused by a faulty damper control, blocked air circulation, or temperature sensor issue. Start by checking the damper door between compartments and verifying proper airflow.
Micro-Air 355 wiring differs from RV Comfort.ZC for multi-zone operation. Zone issues likely from SIG1 and SIG2 wire configuration. Unused Yellow and Orange may be zone 2 controls. Contact Micro-Air technical support for specific wiring guidance.