Solo 401k contribution

I am a sole proprietor and having trouble with solo 401k contributions.  My wife and I each contributed $19,000 (she receives a 1099 from my business).  When I enter these 401k contributions into the "self employed retirement" page there is no change in my federal taxes owed.  This $38,000 total is also not reflected when looking at our net income under Business Income and Expenses (Sch C).  Am I doing something wrong or is there a glitch?