Chevrolet Workshop Manuals
Express 3/4 Ton Van V8-4.8L VIN V (2003)
Power and Ground Distribution > Auxiliary Power Outlet > Component Information > Diagrams > Diagram Information and Instructions > Page 6459
Auxiliary Power Outlet: Diagnostic Aids
Basic Knowledge Required
BASIC KNOWLEDGE REQUIRED
Without a basic knowledge of electricity, it will be difficult to use the diagnostic procedures. You should understand the basic theory of electricity, and
Checking Aftermarket Accessories
CHECKING AFTERMARKET ACCESSORIES
Do not connect aftermarket accessories into the following circuits:
CAUTION: Refer to SIR Caution in Service Precautions.
SIR circuits, all such circuits are indicated on circuit diagrams with the SIR symbol.
NOTE: Refer to OBD II Symbol Description Notice in Service Precautions.
OBD II circuits, all such circuits are indicated on circuit diagrams with the OBD II symbol.
Always check for aftermarket accessories (non-OEM) as the first step in diagnosing electrical problems. If the vehicle is so equipped, disconnect the
Possible causes of vehicle problems related to aftermarket accessories include:
Power feeds connected to points other than the battery
Transceiver wiring located too close to vehicle electronic modules or wiring
Poor shielding or poor connectors on antenna feed line
Check for recent service bulletins detailing installation guidelines for aftermarket accessories.
Inducing Intermittent Fault Conditions
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.
Wiggling the harness
Disconnecting a connector and reconnecting
Stressing the mechanical connection of a connector
Pulling on the harness or wire in order to identify a separation/break inside the insulation
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
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 will not meet the required criteria for the fault condition to appear. In such cases it may be
Salt Water Spray
High Temperature Conditions
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