I was convicted of my first dui in December of 2016, my license was suspended in march of 2017. I never had an ignition interlock installed, and my restricted license will end on March 15th. Will I have to install a device after that date? Or will I be free to reinstate my license without a device?
Ignition interlock is required for six months on any vehicle you drive (there is a limited exception for vehicles owned by the driver's employer) after a DUI conviction. This applies whether driving on a restricted license or after the restriction ends. Since you didn't have a restricted license, the DMV will require interlock when you go to get your license reinstated.
To drive on a restricted license, you need to have an interlock device. If you have a restricted license but have not driven, DMV will require that you imstall an interlock device for at least 6 months and have no positive readings in that time before they will consider reinstating your full driving privileges.