TM 5-3805-292-23
0173
OPEN HARNESS TEST
000173
An open is a failure of an electrical circuit that results in no flow of electrical current. An open circuit is usually
caused by failed electrical wires or a poor connection of electrical connectors. If an electrical wire or a connection
is broken, flow of electrical current through circuit is interrupted. A normal closed circuit will have less than 5 ohms
of resistance.
N OT E
Unless directed to a circuit number with a specific letter designation (for example 120D), perform the open harness
test for all circuits with that number (for example: 120A through 120F).
Test of an Open Circuit
000173
1. Identify connectors and wire numbers of suspect circuits. Use table below to identify circuits as directed in
troubleshooting.
2. Isolate wiring harness by disconnecting suspect component connectors from components and inline wiring
harnesses indicated in table below.
3. At one end of disconnected wiring harness, place a jumper wire from contact of suspect wire to frame ground.
4. At other end of wiring harness, use multimeter probes to measure resistance from contact of suspect wire to
frame ground.
a. If resistance between suspect wire of disconnected connector and frame ground is less than 5 ohms,
harness circuit is OK.
b. If resistance between suspect wire of disconnected connector and frame ground is greater than 5000
ohms, there is an open in harness of suspect wire. Replace harness as indicated in table below.
FROM CONNECTOR
TO CONNECTOR
TM CROSS-REFERENCES
Circuit
Number Connector Cavity/ Schematic
Connector
Cavity/ Schematic
RPSTL Work
(Color)
ID
Pin
Frame
ID
Pin
Frame
Harness
Fig. Package
000G (B)
HJ-C1
E
5
BLOWER
N/A
5
HVAC/HEATER
67
0130
MOTOR
UNIT
003B (P)
HJ-C1
F
5
HJ-C2
2
5
HVAC/HEATER
67
0130
UNIT
004B (Y)
HJ-C1
C
5
HJ-C2
3
5
HVAC/HEATER
67
0130
UNIT
005B (O)
HJ-C1
D
5
HJ-C2
4
5
HVAC/HEATER
67
0130
UNIT
005C (O)
BLOWER
N/A
5
HJ-C2
5
5
HVAC/HEATER
67
0130
MOTOR
UNIT
008B (DB)
HJ-C1
B
5
HJ-C4
1
5
HVAC/HEATER
67
0130
UNIT
009B(DB)
HJ-C1
G
5
HJ-C3
1
5
HVAC/HEATER
67
0130
UNIT
120A (R)
SPLICE60
1
7
1
1
22
Chassis Harness
69
0146
120AA (R)
SPLICE60
1
22
SPLICE1
1
22
Chassis Harness
69
0146
120B (R)
SPLICE1
1
22
FUSE1
D2
10
Chassis Harness
69
0146
120BB (R)
SPLICE60
1
22
SPLICE58
1
22
Chassis Harness
69
0146
0173-7
