Lumina V6-3.1L VIN J (2000)
The fuse is the most common method of an automotive wiring circuit protection. Whenever there is an excessive amount of current flowing through a
circuit the fusible element will melt and create an open or incomplete circuit. Fuses are an one time protection device and must be replaced each time the
circuit is overloaded. To determine if a fuse is open, remove the suspected fuse and examine the element in the fuse for an open (break). If not broken,
also check for continuity using a J 39200 DMM or a continuity tester. If the element is open or continuity is suspect, replace the fuse with one of equal
current rating.
Fusible Link
Fusible link is wire designed to melt and break continuity when excessive current is applied. It is often located between or near the battery and starter or
electrical center. Use a continuity tester or a J39200 DMM at each end of the wire containing the fusible link in order to determine if it is broken. If
broken, it must be replaced with fusible link of the same gage size.
Repairing a Fusible Link
IMPORTANT: Fusible links cut longer than 225 mm (approx. 9 inches) will not provide sufficient overload protection.
Refer to Splicing Copper Wire Using Splice Clips.
Connector Position Assurance (CPA)
The Connector Position Assurance (CPA) is a small plastic insert that fits through the locking tabs of all the SIR system electrical connectors. The CPA
ensures that the connector halves cannot vibrate apart. You must have the CPA in place in order to ensure good contact between the SIR mating
terminals.
Inducing Intermittent Fault Conditions
In order to duplicate the customer's concern, it may be necessary to manipulate the wiring harness if the malfunction appears to be vibration related.
Manipulation of a circuit can consist of a wide variety of actions, including:
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Wiggling the harness
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Disconnecting a connector and reconnecting
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Stressing the mechanical connection of a connector
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Pulling on the harness or wire in order to identify a separation/break inside the insulation
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Relocating a harness or wires
All these actions should be performed with some goal in mind. For instance, with a scan tool connected, wiggling the wires may uncover a faulty input to
the control module. The snapshot option would be appropriate here. Refer to Scan Tool Snapshot Procedure. You may need to load the vehicle in
order to duplicate the concern. This may require the use of weights, floorjacks, jackstands, frame machines, etc. In these cases you are attempting to
duplicate the concern by manipulating the suspension or frame. This method is useful in finding harnesses that are too short and their connectors pull
apart enough to cause a poor connection. A DMM set to Peak Min/Max mode and connected to the suspect circuit while testing can yield desirable
results. Refer to Testing for Electrical Intermittents.
Certainly, using the senses of sight, smell, and hearing while manipulating the circuit can provide good results as well.
There may be instances where circuit manipulation alone won't meet the required criteria for the fault condition to appear. In such cases it may be
necessary to expose the suspect circuit to other conditions while manipulating the harness. Such conditions would include high moisture conditions,
along with exceptionally high or low temperatures. The following discusses how to expose the circuit to these kinds of conditions.
Salt Water Spray
Some compounds possess the ability to conduct electricity when dissolved in water such as ordinary salt. By mixing table salt with water in sufficient
quantities, you can enhance the conductive properties of water so that any circuit which may be sensitive to moisture will more readily fail when
liberally sprayed with this mixture.
Mixing 12 ounces of water with approximately 1 tablespoon of salt will yield a salt solution of 5%. Fill a normal spray bottle with this mixture. This
mixture is sufficient to enhance the water's own conductivity. This may cause the circuit to fail more easily when sprayed. Once the mixture is
completed, spray the suspect area liberally with the solution. Then, while monitoring either a scan tool or DMM, manipulate the harness as discussed
previously.
High Temperature Conditions
If the complaint tends to be heat related, you can simulate the condition using the J 25070 Heat Gun.
Using the heat gun, you can heat up the suspected area or component. Manipulate the harnesses under high temperature conditions while monitoring
the scan tool or DMM to locate the fault condition.
The high temperature condition may be achieved simply by test driving the vehicle at normal operating temperature. If a heat gun is unavailable,
consider this option to enhance your diagnosis. This option does not allow for the same control, however.
Low Temperature Conditions
