K 1500 Truck 4WD V8-4.8L VIN V (1999)
Intermittent & Poor Connections Diagnosis
Repair and Verify Fix
From isolating the root cause, basically the problem has been diagnosed. Using the Component Location Table and the corresponding figure,
quickly find C100 and the LT GRN wire, locate the exact trouble point and make the repair.
Check the thoroughness of the repair by performing a final system check on the headlamp circuit. This of course means making sure that both high
beams, both low beams, and the high beam indicator are working.
Testing For Electrical Intermittents
Perform the following procedures while wiggling the harness from side to side. Continue this at convenient points (about 6 inches apart) while watching
the test equipment.
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Testing for Short to Ground
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Testing for Continuity
If the fault is not identified, perform the procedure below using the MIN MAX feature on the J 39200 DMM. This feature allows you to manipulate the
circuit without having to watch the J 39200. The J 39200 will generate an audible tone when a change is detected.
IMPORTANT: The J 39200 must be used in order to perform the following procedure since the J 39200 can monitor current, resistance or voltage
while recording the minimum (MIN), and maximum (MAX) values measured.
1. Connect the J 39200 to both sides of a suspected connector (still connected), or from one end of a suspected circuit to the other. Refer to
Troubleshooting with a Digital Multimeter for information on connecting the J 39200 to the circuit.
2. Set the rotary dial of the J 39200 to the V (AC) or V (DC) position.
3. Press the range button of the J 39200 in order to select the desired voltage range.
4. Press the MIN MAX button of the J 39200. The J 39200 displays 100 ms RECORD and emits an audible tone (beep).
IMPORTANT: The 100 ms RECORD mode is the length of time an input must stay at a new value in order to record the full change.
5. Simulate the condition that is potentially causing the intermittent connection, either by wiggling the connections or the wiring, test driving, or
performing other operations.
6. Listen for the audible Mm Max Alert which indicates that a new minimum or maximum value has been recorded.
7. Press the MIN MAX button once in order to display the MAX value and note the value.
8. Press the MIN MAX button again in order to display the MIN value and note the value.
