Fault finding – Introduction23A
23A - 5V4 MR-372-J84-23A050$066.mif
Vdiag No.: 10-11-15
4. FAULT FINDING PROCEDURE (continued)
Fault finding problems
Disconnecting the connectors and/or manipulating the wiring harness may temporarily remove the cause of a fault.
Electrical measurements of the voltage, resistance and insulation are generally correct, especially if the fault is not
present when analysing (stored fault).
Look for damage under the bonnet and in the passenger compartment.
Carefully check the fuses, insulators and wiring harness routing.
Look for signs of oxidation.
While manipulating the wiring harness, use the diagnostic tool to note any change in fault status from stored or
Check that the connectors are correctly locked.
Apply light pressure to the connectors.
Twist the wiring harness.
If there is a change in status, try to locate the source of the fault.
Inspection of each component
Disconnect the connectors and check the appearance of the clips and tabs, as well as the crimping (no crimping on
the insulating section).
Check that the clips and tabs are correctly locked in the sockets.
Make sure that no clips or tabs have been dislodged during connection.
Check the clip contact pressure using an appropriate model of tab.
Check the continuity/insulation
Check the continuity of entire lines, then section by section.
Look for a short circuit to earth, to + 12 V or to another wire.
If a fault is detected, repair or replace the wiring harness.