AUTONATOMY / ELECTRICAL LAB
02 Electrical & Electronics Fundamentals → Wiring Diagrams, Harnesses & Connectors → Mini Course 06
THE CHALLENGER • INTERACTIVE

Wiring Faults &
Intermittent Circuit Diagnosis

Make a fault appear. Collect evidence while it is present. Find the precise failure—without replacing a good component.

10 short lessonsLive circuit & meterTrigger-based faultsMystery diagnostic missions
Your course progress0 / 10 lessons • Assessment pending

01 / Learn the fault

Lesson 1 of 10

02 / Circuit workbench

12.6 V • 10 A fuse • 6 Ω lamp

Model: a simplified, fused 12 V lamp circuit with a power wire, in-line connector, load and chassis ground. Component labels are educational, not OEM pinouts.

Environmental triggers

Intermittent faults are only present under their triggering conditions. For a broken wire or loose terminal, vibration alternates the connection between good and faulty.

Fuse intact
10 A FUSESWITCHC16 Ω LAMP12.6 VCHASSIS / BATTERY NEGATIVESelect a test point, then tap + or − in the meter panel.
LampON
Current2.04 A
Load voltage12.3 V
Power25.0 W

03 / Virtual meter & scope

DC volts: select two test points. Voltage displayed = potential at red lead − potential at black lead. A voltage-drop test is performed across a connection while the circuit is carrying current.

Selecting RED
Meter • DC volts0.00 V
Scope • selected point0.00 V
Recent samples → rightScope: TP3

Suggested evidence

Power-side drop (TP0 → TP3)
Ground-side drop (TP4 → TP5)
Voltage across load (TP3 → TP4)

TP0 battery positive • TP1 after fuse • TP2 after switch • TP6 connector input • TP3 connector output / lamp feed • TP4 lamp return • TP5 chassis ground.

04 / The Challenger's mystery bay

Mission 1

Load a hidden fault, reproduce the symptom, make measurements, then identify the best-supported fault. The same circuit model powers the mystery bay and the workbench above.

No mystery loaded
Customer statement

The lamp sometimes stops working. The customer reports that the symptom is difficult to duplicate.

Evidence notebook

No readings logged.

Technician's workflow

1. Verify complaint; note when it occurs.
2. Reproduce with vibration, heat, or moisture.
3. Compare power-side and ground-side voltage drops under load.
4. Isolate the affected section; inspect and repair per service information.
5. Recheck under the original triggering condition.

05 / Final knowledge check

Six questions. Score at least five correct to pass; you can retry. Use observations from the virtual lab before deciding.