How one would even attempt to restart Mars' magnetic field, though, I have no idea.
Discussion
sounds like you got your hands full...
good luck!
who said it ever had one?
maybe magnetic fields are only present when there is sufficient mass to cause the core to be supercritical (above boiling point but solid)
I saw calculations once that showed, no matter your plan to induce a field, it would take on the order of 100,000 years for the field to stabilize. The planet fights back with an opposing field until you can saturate all the layers. Mumble mumble skin effect or something.