TM 5-3805-291-23-1
ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
0013 00
WIRING HARNESS (SHORT CIRCUIT) TEST
0013 00
N OT E
Short circuit is failure of elecrical circuit that results in undesired electrical current. Usually,
t
short circuit is bypass of circuit across load. For example, short across wires in circuit for lamp
produces too much current in wires but no current is felt at lamp. Lamp is shorted out. Resistance
in normal circuit can vary, but resistance between particular circuit and other unrelated circuits
is always greater than 5,000 Ohms. This test is for a short circuit.
For complete electrical schematic, refer to WP 0237 00.
Identify connectors and wire numbers of suspect circuits. Use Schematics (WP 0237 00) to identify circuits.
1.
2.
Turn engine start switch and battery disconnect switch to OFF position (TM 5-3805-291-10).
3.
Disconnect component and ECM from wiring harness.
4.
At wiring harness connector for ECM, place one multimeter probe on contact of suspect wire.
5.
Use other multimeter probe to check resistance across all other contacts in connector(s) of ECM and frame ground.
Expected Results. Resistance is greater than 5,000 Ohms for all measurements.
6.
a.
If results are OK, harness circuits are correct. Connect component and ECM to wiring harness.
b.
If results are NOT OK, a short exists in wiring harness between suspected wire and wire with lowest resistance
measurement. Replace wiring harness in question (WP 0195 00 thru WP 0201 00).
