2001 Lincoln Navigator

My 2001 linconl navigator air suspension is not working the air compressor seems to not be working I just replace it three weeks ago is new what could be the problem and a relay is also new it had the same prolblem three weeks ago
January 12, 2011.

Check to see if the compressor is getting power. If there is not power, the only thing you can do is start tracing wires to see where the power is lost.