The theory of magnetohydrodynamic "switch-on" shock waves is well understood when the electrical conductivity is large ahead of the shock front. If the conductivity is zero, the analysis is more difficult. Kulikovskii and Lyubimov have shown in principle how the solution proceeds in this case; there are two regions in the shock front, separated by a temperature T* above which the electrical resistivity is smaller than the viscosity and thermal conductivity. We apply this general theory to the switch-on ionizing shock wave, and we provide a method for calculating T*. The shock velocity and the flow parameters behind the front are then obtained in terms of the parameters ahead of the front and the magnitude of the jump in the transverse magnetic field.