Packaged refrigeration unit Troubleshooting... Let's start by finding out what is running and what's not? The fans, compressor(s), etc. If a component is not running, let's find out why. Is it getting voltage? Are the motor windings open or possibly a bad capacitor? If all components are running, check air flow first before gauging up. Check supply and return air temperatures. This is a basic refrigeration troubleshooting course from Interplay Learning. They have many courses to enroll in for in