Chevrolet Workshop Manuals
Astro Van 2WD V6-4.3L VIN W (2001)
Relays and Modules > Relays and Modules - Accessories and Optional Equipment > Accessory Delay Module > Component Information > Diagrams > Diagram Information and Instructions > Page 14
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
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
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
A DMM should be used instead of a test lamp in order to test for voltage in high impedance circuits. While a test lamp shows whether voltage is present,
The ohmmeter function on a DMM shows how much resistance exists between 2 points along a circuit. Low resistance in a circuit means good
IMPORTANT: Disconnect the power feed from the suspect circuit when measuring resistance with a DMM. This prevents incorrect readings. DMMs
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
Following are examples of the various methods of connecting the DMM to the circuit to be tested:
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
Disconnect the harness at both ends of the suspected circuit where it connects either to a component or to Other harnesses.
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
Fused Jumper Wires
J 36169-A Fused Jumper Wire
IMPORTANT: A fused jumper may not protect solid state components from being damaged.
The J 36169-A includes small clamp connectors that provide adaptation to most connectors without damage. This fused jumper wire is supplied with a
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
This may require the use of weights, floorjacks, jackstands, frame machines, etc. In these cases you are attempting to duplicate the concern by
Certainly, using the senses of sight, smell, and hearing while manipulating the circuit can provide good results as well.
|[PREV PAGE] [NEXT PAGE]|