American Airlines Logo Light Harness Troubleshooting

Competitors Required:

1

Description:

Competitors will troubleshoot electrical Harness of an inoperable logo light

References:

• Fluke 77/75/23/21 Series III Multimeter Instruction Sheet
• Electrical schematic (provided at the event)
• Worksheet (provided at the event)

Tools, Equipment, and Materials Provided:

Digital Fluke Multimeter with leads

Snap-on provided tooling (qty one in each of two pallets unless otherwise indicated):

Cannon plug pliers with grips (ATI508KG)

Procedures:

1. Deactivate the logo light system.
   1. Select the LOGO LIGHT switch to OFF.
   2. Pull and collar the logo light circuit breaker.
2. Remove the electrical wiring harness.
3. Using the provided electrical schematic and multimeter, perform the following wire checks to determine the condition of each wire in the electrical logo light harness (resistance, continuity, or open circuit).
4. Find the wire termination data. Refer to the electrical schematic.

WARNING: EACH CONNECTOR ON THE CIRCUIT THAT REQUIRES TESTING MUST BE DISCONNECTED. IF THE CONNECTORS ARE NOT DISCONNECTED, UNSATISFACTORY RESISTANCE INDICATIONS OR DAMAGE TO THE CONNECTOR CAN OCCUR.

WARNING: DO NOT BEND OR PUT STRESS ON THE CONTACTS. DAMAGE TO THE CONNECTOR OR THE CONTACTS CAN OCCUR.

1) Wire Continuity / Resistance Check

1. Select the multimeter.

WARNING: DO NOT USE A MEGOHMMETER FOR THE INSULATION RESISTANCE TEST OF THE ON-WING WIRING REPAIR. INJURY TO PERSONNEL OR DAMAGE TO THE AIRPLANE CAN OCCUR.

2. Set the meter to the proper selection (refer to the multimeter instructions).
3. Attach one meter test lead to WIRE PIN 1 on the “A” connector plug assembly.
4. Check continuity on all pins on the “B” plug.
5. Use the wiring diagram and meter readings to record any discrepancies or faults found on the worksheet.

NOTE: Use the discrepancy codes listed on the score sheet to describe faults found in the harness. Identify the plug (A or B), pin (1 through 7), and corresponding fault code (1 through 3). Example: A5 to B3 #3 = Plug A, Pin 5 to Plug B, Pin 3, fault #3 (CONTINUITY).

6. Continue the continuity check. Repeat steps c) through e) for the remaining WIRE PIN contacts on the “A” connector plug (pins 2 through 7).
7. Attach one meter test lead to WIRE PIN 1 on the “B” connector plug assembly.

NOTE: Reversing the troubleshooting process will locate diodes in the wiring system, if installed.

8. Check continuity on all pins on the “A” plug.
9. Use the wiring diagram and meter readings to record any discrepancies or faults found on the worksheet.

NOTE: Use the discrepancy codes listed on the score sheet to describe faults found in the harness. Identify the plug (A or B), pin (1 through 7), and corresponding fault code (1 through 3). Example: A5 to B3 #3 = Plug A, Pin 5 to Plug B, Pin 3, fault #3 (CONTINUITY).

10. Repeat steps g) through i) for the remaining WIRE PIN contacts (pins 2 through 7) on the “B” connector plug, and record any discrepancies or faults found on the worksheet.

2) Plug Integrity Check

1. Attach one meter test lead to WIRE PIN 1 on the “A” connector plug assembly.
2. Connect the other meter test lead to all other WIRE PIN contacts on the “A” connector plug.
3. Continue the integrity check: check pin 2 against all other pins, then pin 3 against all other pins, and so on until all pins have been checked.
4. Use the wiring diagram and meter readings to record any discrepancies or faults found on the worksheet.

NOTE: Use the discrepancy codes listed on the score sheet to describe faults found in the harness. Identify the plug (A or B), pin (1 through 7), and corresponding fault code (1 through 3). Example: A5 to B3 #3 = Plug A, Pin 5 to Plug B, Pin 3, fault #3 (CONTINUITY).

5. Repeat steps a) through c) for the “B” connector plug, and record any discrepancies or faults found on the worksheet.

3) Backshell Check

1. Attach one meter test lead to the backshell.
2. Use the other meter test lead on the WIRE PIN assemblies in the same connector plug.

WARNING: DO NOT BEND OR PUT STRESS ON THE CONTACTS. DAMAGE TO THE CONNECTOR OR THE CONTACTS CAN OCCUR.

3. Read the meter. Make sure that the resistance shown on the meter is open or 100 megohms.
4. Repeat steps a) through c) for each WIRE PIN assembly in the connector plug.
5. If the backshell test fails, record the discrepancy on the worksheet.

NOTE: Use the discrepancy codes listed on the score sheet to describe faults found in the harness. Identify the plug (A or B), pin (1 through 7), and corresponding fault code (1 through 3). Example: A5 to B3 #3 = Plug A, Pin 5 to Plug B, Pin 3, fault #3 (CONTINUITY).

Task Completion

1. Request and replace the harness with the new one provided by the judge.
2. Reactivate the logo light system.
3. Verify that the logo light operates.
4. Return tools to the shadow board and clean up the work area.
5. Tell the judge when you have completed the task.

Optional bonus questions will be available on the worksheet. Contestants may answer them with any remaining time to receive a time deduction.