We performed a test using a splitter or "Y" cable to find out. Results have varied but the outcome is the same in that the ELDs interfere with one another and does not produce accurate data. Issues include: split trips, missing trips, high fuel consumption data, incorrect high RPM alerts, and incorrect speeding alerts. Our team investigated further and found that there is no splitter cable available in the market that is capable of supporting two ELDs at once. Please contact FleetUp Support at support@fleetup.com or call 855-274-2886 option 3 for more information.