TM 5-3810-307-24-1-2
5b. ANTI-TWO BLOCK PROBLEM (DOUBLE SWITCH) cont'
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Turn system power off and disconnect blue wire from terminal X1:35 in central unit.
Check anti-two block signal in central unit with ohmmeter.
Measure between blue wire disconnected from X1:35 and terminal X1:34 on connection board.
Anti-two block switch(es) closed = 4700 Ohms 500 Ohms
Anti-two block switch(es) open => 1 Megaohm.
Refer to Drawing 2, 3, 14, 22 in Section 10.
Correct?
NO
Faulty wiring between boom base junction box and
central unit. Check cable.
YES
Tag and disconnect wires from X1:34 and X1:35 on connection board in central unit.
Check main board function by installing a temporary resistor,
4700 Ohms, between X1-35 and X1-34 on connection board in central unit.
With resistor connected and power on to central unit, the anti-two block alarm should be inactive.
Refer to Drawing 2, 3, 15 in Section 10.
Defect on main board in central unit. Replace main board and
Correct?
NO
reset pressure channel. Refer to Drawings 1, 3 in Section 10
and Procedures 3 and 4 in Section 11.
YES
Reconnect Gray wire to X1:34 and blue wire to X1:35 on connection board in central unit.
Refer to Drawings 2, 3 in Section 10.
END
Change-1 G-17
