  Measurements of Nernst effect, resistivity and Hall angle on epitaxial films
of Y$_{1-x}$Pr$_x$Ba$_2$Cu$_3$O$_{7-\delta}$(Pr-YBCO, 0$\leq x\leq$0.4) are
reported over a broad range of temperature and magnetic field. While the Hall
and resistivity data suggest a broad pseudogap regime in accordance with
earlier results, these first measurements of the Nernst effect on Pr-YBCO show
a large signal above the superconducting transition temperature(T$_c$). This
effect is attributed to vortex-like excitations in the phase incoherent
condensate existing above T$_c$. A correlation between disorder and the width
of the phase fluctuation regime has been established for the YBCO family of
cuprates, which suggests a T$_c\approx$110K for disorder-free
YBa$_2$Cu$_3$O$_{7-\delta}$.
