Wiring power cord plug. C-51

[mllaugh3]

I have a Cavalier V-51 that had a bad plug on the cord.  Bought a new one and wanted to make sure on the correct wiring.  I hooked the black to the copper screw and the white to the brass screw.  Plugged in and the fans run but the compressor isn't getting cold.  Does it make a difference which wire goes to which screw?  Thanks for any help.

[GvtProprty]

The way they taught it to us in electrician's mate school was "black is brass you bet your @$$". That way any switches downstream open the hot wire rather than the neutral. That being said, the electrons don't care which way they go. Is your thermostat working or the compressor start relay?