Fault detection and isolation in automotive wiring harness

An automotive electrical system comprising, a plurality of electrical devices (21,22,23) including at least one termination device (21), and a wiring harness system interconnecting said electrical components (21,22,23) and including a plurality of harness conductors (28) interconnected by a plurality of connectors (25,26), one of said connectors being a termination connector (26-1) connected to said termination device (21), said wiring harness system including a dedicated test line comprising a termination conductor disposed in said termination connector and comprising more than one of said harness conductors, said dedicated test line (55) further comprising at least one test point (56) for testing the interconnection of said termination conductor with said dedicated test line.