DeVille DHS V8-4.6L VIN Y (2000)
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Diodes and solid state components in a circuit can cause a DMM to display a false reading. To find out if a component is affecting a measurement take a
reading once, then reverse the leads and take a second reading. If the readings differ the solid state component is affecting the measurement. Following
are examples of the various methods of connecting the DMM to the circuit to be tested:
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Backprobe both ends of the connector and either hold the leads in place while manipulating the connector or tape the leads to the harness for
continuous monitoring while you perform other operations or test driving. Refer to Probing Electrical Connectors.
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Disconnect the harness at both ends of the suspected circuit where it connects either to a component or to other harnesses.
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If the system that is being diagnosed has a specified Pinout or breakout box, it may be used in order to simplify connecting the DMM to the circuit
or for testing multiple circuits quickly.
Probing Electrical Connectors
IMPORTANT: Always be sure to reinstall the Connector Position Assurance (CPA) and Terminal Position Assurance (TPA) when reconnecting
connectors or replacing terminals.
FRONTPROBE
Disconnect the connector and probe the terminals from the mating side (front) of the connector.
NOTE: Do not insert test equipment probes into any connector or fuse block terminal. The diameter of the test probes will deform most terminals. A
deformed terminal can cause a poor connection, which can result in system failures. Always use the J 35616-A Connector Test Adapter Kit or the J
42675 Flat Wire Probe Adapter Kit in order to frontprobe terminals. Do not use paper clips or other substitutes as they can damage terminals and
cause incorrect measurements.
BACKPROBE
Do not disconnect the connector and probe the terminals from the harness side (back) of the connector.
IMPORTANT:
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Backprobe connector terminals only when specifically required in diagnostic procedures.
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Do not backprobe a sealed (Weather Pack(R) connector, less than a 280 series Metri-Pack connector, a Micro-Pack connector, or a flat wire (dock
and lock) connector.
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Backprobing can be a source of damage to connector terminals. Use care in order to avoid deforming the terminal, either by forcing the test probe
too far into the Cavity or by using too large of a test probe.
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After backprobing any connector, inspect for terminal damage. If terminal damage is suspected, test for proper terminal contact.
Test Lamp
NOTE: Refer to Test Probe Notice in Service Precautions.
A test lamp can simply and quickly test a low impedance circuit for voltage.
The J 34142-B Test Lamp is Micro-Pack compatible and comprised of a 12 volt light bulb with an attached pair of leads.
To properly operate this tool use the following procedure.
1. Attach one lead to ground.
2. Touch the other lead to various points along the circuit where voltage should be present.
3. When the bulb illuminates, there is voltage at the point being tested.
Fused Jumper Wires
IMPORTANT: A fused jumper may not protect solid state components from being damaged.
The J 36169-A fused jumper includes small clamp connectors that provide adaptation to most connectors without damage. This fused jumper wire is
supplied with a 20 A fuse which may not be suitable for some circuits. Do not use a fuse with a higher rating than the fuse that protects the circuit being
tested.
Repairing Damaged Wire Insulation