Case IH AFX8010 Repair Manual page 1809

BODY AND STRUCTURE - SAFETY SECURITY ACCESSORIES Safety
Sensing system Rear ladder sensor - Open circuit (E.50.B.95.80 -
G.30.B.50)
AFX8010
E0026-05 - Rear Ladder Sensor
Cause:
The rear ladder sensor (B-22) circuit is open.
Possible failure modes:
1. Sensor supply wiring is open.
2. Controller internal failure (internal regulator failure).
Solution:
1.
Enter the Universal Display Plus "DIAG" screen. Select the "GRAIN HANDLING" or "THRESHING" sort menu,
and select "REAR LADDER SEN" to check the voltage range.
The proper voltage for sensor when rear ladder is up is 0.5 - 3.9 volts
The proper voltage for sensor when rear ladder is down is 3.9 - 4.9 volts
The proper voltage with sensor disconnected is 4.9 - 5.2 volts.
A. If the voltage reading is high 4.9 - 5.2 volts, continue with Step 2.
B. If the voltage reading is within the proper limits, the open is not present at this time. Continue the
troubleshooting at Step 9.
NOTE: Visually inspect the wiring harness and connectors. Verify that the connector was fully installed.
Inspect the terminals and wires at the connector for pushed back or corroded terminals or damaged wires.
Flex the harnesses involved to reveal intermittent breaks or shorts in the wiring concerned.
2.
Disconnect the rear ladder sensor connector X251. Use a jumper wire to short the harness end of connector
X251 pin 2 to chassis ground.
A.
If the voltage drops to 0 - 0.5 volts indicating a ground, the open circuit is not in the supply side of the
circuit. Continue with Step 5.
B. If the monitor still displays 4.9 - 5.2 volts, continue with Step 3.
3. Disconnect the straw hood rear (SH) harness from the straw hood front (SW) harness at connector X071.
Use a jumper wire to short connector X071 pin 11 to chassis ground.
A. If the voltage drops to 0 - 0.5 volts indicating a ground, the open circuit is in the straw hood rear
(SH) harness between connector X071 pin 11 and connector X251 pin 2 wire 570 yellow. Locate
the open and repair.
B. If the monitor still displays 4.9 - 5.2 volts, continue with Step 4.
4. Disconnect the straw hood front (SW) harness from the main frame (MF) harness at connector X024. Use a
jumper wire to short connector X024 pin 16 to chassis ground.
A. If the voltage drops to 0 - 0.5 volts indicating a ground, the open circuit is in the straw hood front
(SW) harness between connector X024 pin 16 and connector X071 pin 11 wire 570 yellow. Locate
the open and repair.
B. If the monitor still displays 4.9 - 5.2 volts, the open circuit is in the main frame (MF) harness between
connector X024 pin 16 and connector X019 pin J2-17 wire 570 yellow. Locate the open and repair.
5.
Disconnect the rear ladder sensor connector X251. Use a multimeter to check for continuity between the
harness end of connector X251 pin 1 and chassis ground.
9703 1 27/05/2004
E.50.B / 13