Wiring Harness & Electrical Connectors
Many intermittent open or shorted circuits come and go with harness or connector movement caused by vibration, engine torque, and bumps or rough pavement.
Test for intermittents by moving related connectors and wiring while monitoring appropriate scan tool data. With engine running, move related connectors and wiring while monitoring engine operation. Verify if harness or connector movement affects scan tool data display, component or system operation, or engine operation. Repair condition as necessary.
Intermittents caused by electrical connectors are usually caused by poor electrical connections, terminal tension and/or wiring problems.
Check for poor mating of connector halves, terminals backed out or not fully seated in connector body, improperly formed or damaged terminals or poor terminal tension. Also check for poor terminal-to-wire connections including terminals crimped over insulation, swollen and stiff sections of wire in suspect circuits, wires that are broken inside the insulation, pinched, cut or rubbed through wiring or wiring that is in contact with hot exhaust components. Repair condition as necessary.