My van will not start? on 2000 Chrysler Town & Country

I replaced the transmission on my Chrysler Town and Country van and now it won't start.

Asked by for the 2000 Chrysler Town & Country
By will not start do you mean it will not crank or do you mean it cranks but will not fire off? Please be specific.
It will not engage starter. Everything else works but when Itry to crank it will not make any noise like trying to crank or anything. Someone told me that it may a neutral safety switch but I don't know. And where would that be located?