I have what appears to be new working parts from an AC/DC refigeration system. The stuff looks identical to many of the upright units I've seen on motorboats. I have the compressor, eveaprator and condenser all hooked up and charged but no instructions. I applied 12 volts DC to the compressor and it didn't run. I also tried 24 volts and it didn't run. Do these units actually run on AC current? Does anyone know the power requirements on that type system. Sorry, there is no writing or name on the stuff. Barry