Works with tractor present or without the tractor present
Bosch ESI[truck] trailer ABS coverage for Bendix, Haldex,Meritor Wabco and Wabash systems
External power supply is necessary without tractor
The ESI 3824-06 7-pin trailer adapter allows direct connection to the trailer with or without the tractor present. The 3824 ESI has extensive trailer systems coverage including ABS.