We report a tunneling study between ${\mathrm{Pr}}_{2$-${}x}{\mathrm{Ce}}_{x}{\mathrm{CuO}}_{4$-${}$δ${}}$ and lead as a function of doping, temperature, and magnetic field. The temperature dependence of the gap follows the BCS prediction. Our data fit a nonmonotonic $d$-wave order parameter for the whole doping range studied. From our data we are able to conclude that the electron-doped cuprate ${\mathrm{Pr}}_{2$-${}x}{\mathrm{Ce}}_{x}{\mathrm{CuO}}_{4$-${}$δ${}}$ is a weak-coupling BCS dirty superconductor.