Three-wire installations are not compliant with the ELD mandate. You can read our blog for more information on the ELD mandate.
If you are operating a Commercial Motor Vehicle (CMV) that is before model year 2000, you are exempt from the ELD mandate, and can continue to log on paper. This is because many vehicles manufactured before 2000 do not have an electronic control module (ECM). An ECM provides the ELD system with the required engine data needed to comply with the mandate.