Read the schematic. Trace the current path. Gather measurements. Diagnose the fault. Verify the repair. This is a fictional 12.6 V teaching circuit, not an OEM vehicle wiring diagram.
Mission briefing
Your vehicle has two electrical loads—a headlamp and a cooling fan—sharing a protected main feed and ground. Each branch includes its own fuse, control, connector and load. The fan uses a relay. The Challenger has hidden six wiring and component faults inside the system.
10short review lessons
5hands-on virtual labs
6evidence-based diagnostic missions
8 / 10passing assessment score
Your win condition: Complete 10 lessons, five labs, all six diagnostic missions and their repair verifications, then pass the final assessment. Progress stays in this browser when local storage is available.
Safety boundary
The measurements are modeled for instruction. Real vehicles require the correct OEM procedure, connector-face orientation and safe probing equipment. Never measure resistance on an energized circuit or jumper unknown terminals. De-energize and isolate circuits before inspecting or repairing wiring. High-voltage systems are excluded from this low-voltage lab.
Lab 01 · Identify what you're testing
Inspect at least six of the eight devices below. Click a device to see its role, schematic label and an appropriate testing question. The physical component location is not implied by where its symbol appears on the schematic.
Select a component to inspect it.
0 / 6 inspected
Lab 02 · Trace the electrical paths
Select a path to highlight it, operate both controls and inspect the labeled devices or test points. Trace all four paths before completing this lab. Arrows indicate conventional current from source toward return, not electron motion.
L1: ONHeadlamp branch
M1: ONFan branch
12.4 VCommon bus under load
0.2 VShared ground vs B−
Select a path, device, or numbered test point for a description.
0 / 4 paths traced
Lab 03 · Virtual multimeter
All voltage readings are simulated DC for the current circuit state. Select two distinct leads, then measure the potential difference red minus black. Switch both loads on in the Trace lab to create a meaningful loaded test.
— VChoose your probes
Perform each of these three measurements: source voltage (B+ to B−), headlamp load voltage (L1+ to L1−), and shared ground drop (G100 to B−) with both loads operating. Do not mistake a no-load voltage check for a loaded circuit test.
Red
Black
Reading
Lab 04 · The Challenger's Six Diagnostic Missions
Choose a complaint. The fault label stays hidden until you gather evidence and submit a diagnosis. Use the Trace lab to familiarize yourself with the circuit first. In each mission measure at least two distinct points with the loads commanded on, then choose one supported fault. You can also compare the return side of a load against battery negative.
— VSelect two different points
Test
Reading
Condition
Choose your diagnosis
0 / 6 diagnosed
Lab 05 · Repair and verify
Diagnosing a fault is not the same as proving a repair. For each mission you diagnosed, simulate the appropriate OEM-approved repair, command both loads on, take a post-repair measurement and verify that the complaint is gone. An intermittent fault must also be checked under its triggering condition.
0 / 6 verified
Final assessment
Use circuit theory and diagnostic evidence—not guesses. Pass at least 8 out of 10 questions. Retakes are available. Your completion badge requires all ten lessons, five labs, six diagnoses, six verified repairs and a passing score.
🏅 The Challenger: Capstone Complete
You completed the simulated wiring, harness and connector capstone, verified six repairs and passed the assessment. This is an educational completion badge, not an ASE certification or professional credential.