K Yukon/Denali 4WD V8-5.7L VIN R (2000)
Testing For Short To Ground
NOTE: Refer to Test Probe Notice in Service Precautions.
The following procedures test for a short to ground in a circuit.
With a DMM
1. Remove the power feed (i.e. fuse, control module) from the suspect circuit.
2. Disconnect the load.
3. Set the rotary dial of the DMM to the ohm position.
4. Connect one lead of the DMM to one end of the circuit to be tested.
5. Connect the other lead of the DMM to a good ground.
6. If the DMM does NOT display infinite resistance (OL), there is a short to ground in the circuit.
With a Test Lamp
1. Remove the power feed (i.e. fuse, control module) from the suspect circuit.
2. Disconnect the load.
3. Connect one lead of the test lamp to battery positive voltage.
4. Connect the other lead of the test lamp to one end of the circuit to be tested.
5. It the test lamp illuminates, there is a short to ground in the circuit.
Fuse Powering Several Loads
1. Review the system schematic and locate the fuse that is open.
2. Open the first connector or switch leading from the fuse to each load.
3. Connect a DMM across the fuse terminals (be sure that the fuse is powered).
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When the DMM displays voltage the short is in the wiring leading to the first connector or switch.
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If the DMM does not display voltage refer to the next step.
4. Close each connector or switch until the DMM displays voltage in order to find which circuit is shorted.
Connector Test Adapters
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.
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.
Digital Multimeter
NOTE: Refer to Test Probe Notice in Service Precautions.
IMPORTANT: Circuits which include any solid state control modules, such as the PCM, should only be tested with a 10 megohm or higher impedance
digital multimeter such as the J 39200.
The J 39200 Instruction Manual is a good source of information and should be read thoroughly upon receipt of the DMM as well as kept on hand for
