Other Electrical Fault Tracing

Faults in the electrical system can be caused by wiring and connectors. These faults may occur due to interference from other electrical systems and mechanical or chemical damage.

LA1: Check Connectors Visually






Whenever a connector is disconnected for measurements or checks, it should be checked visually. Look for oxidation which could affect contact in the connectors. Check pins and ensure that the copper conductor makes good contact with the pin.

LA2: Break In The Circuit






A break in the circuit is indicated by the loss of a function. Worn wiring and connectors which have come loose are common causes of faults. Disconnect the connectors at both ends of the lead. Measure with an ohmmeter at both ends of the lead. Ohmmeter should indicate approx. 0 Ohm on a fully intact lead.

Checks for Intermittent breaks:
Carry out an visual check of the lead as per LA1.
Shake the lead gently and gently pull the connectors during the ohmmeter reading to identify the location of the break.


LA3: Grounding

Grounding is often indicated by the fuse blowing when a voltage is passed through the wiring.






Activate all switches and sensors in the circuit and check to see if the fuse blows. Gently shake the wiring and pull the terminals while taking readings in order to detect intermittent faults. Disconnect circuit component connectors so that these do not affect readings.

Using an ohmmeter measure the resistance between the wiring and ground (GND) to detect any grounding. The ohmmeter should read infinite resistance when no components are connected.





LA4: Short Circuits

Short circuits do not always blow the fuse. The fault is most often indicated by the loss of a function.





Gently shake the wiring and pull the terminals while taking readings in order to detect intermittent faults. Using a voltmeter take readings at various points in the circuit while activating switches and sensors.





The voltage indicated by the voltmeter depends on the circuit which is being measured and the position of switches and sensors. Use the circuit diagram to find the correct voltage in the circuit. Using an ohmmeter take readings between suspected wires in order to locate short circuits. The ohmmeter should read infinite resistance between wires which are not connected to each other in the circuit.


LA5: Loose Contact (Intermittent Break)






Loose contact in connectors is caused by the oxidation of pins and contacts or poorly connected wiring. Trace for faults in the same way as for breaks.


Disconnect the connectors at both ends of the wiring. Take readings using an ohmmeter or multimeter. (LA1) Gently shake wiring and pull connectors while taking readings to find loose contacts. The ohmmeter should read approx. 0 Ohm..


LA6: Contact resistance in connectors

The resistance of contacts, wirings and connectors should ideally be 0 Ohm. However there may be some resistance because of poorly connected wiring, oxidation on connectors and wear.If resistance becomes too great functions will be interrupted. The magnitude that this resistance must reach before there is interference varies with the load on the circuit. A guideline is a few Ohm.


Cleaning of female contacts and male tabs. Disconnect battery negative terminal. Spray anti-rust spray 1161034-2 on the two connectors.Blow clean with compressed air. Wear suitable eye protection.





NOTE: Do not fill the cover with grease.


Greasing the female contacts
Press in grease 1161417-9 into the female contacts directly from the tube.





Check that the recesses are filled in all the connector sockets. Use a separate male tab to check that the female tab offers proper contact and to see that it stays in place if you pull the male tab gently.