ELECTRICAL SYSTEM TESTS, INSPECTIONS, AND ADJUSTMENTS - CONTINUED
WIRING HARNESS (OPEN CIRCUIT) TEST
N OT E
Open circuit results in no flowof electrical current. Open circuit is usually caused by failed or
corroded electrical wires or poor connection of electrical connectors. If electrical wire or connec-
tion is broken, flow of electrical current through circuit is interrupted. Normally, closed circuit
will have less than 5 Ohms of resistance.
For complete electrica schematic, refer to Schematics (WP 0237 00).
For a better understanding of each sytem, review appropriate section in Theory of Operation
These procedures may give direcion to replace wiring harnesses. However, limited repair of wir-
ing harnesses is authorized. Refer to Electrical General Maintenance Instructions (WP 0022 00)
for correct repair procedures.
Identify connectors and wire numbers of suspect circuits. Use Schematics (WP 0237 00) to identify circuits.
Turn engine start switch and battery disconnect switch to OFF position (TM 5-3805-291-10).
Disconnect component and Electronic Control Module (ECM) from wiring harness.
At one disconnected harness connection, place jumper wire from contact of suspect wire to frame ground.
At other wiring harness connector, use multimeter probes to measure resistance from contact of suspect wire to frame
If results are OK, circuit is correct. Connect component and ECM to wiring harness.
If results are NOT OK, there is an open circuit in wiring harness. Replace wiring harness in question (WP 0195 00
thru WP 0201 00).