Turn Signal & Hazard Light Lab
Operate a virtual vehicle’s left and right turn indicators, switch on the hazard lights, then inject faults and diagnose the circuit from its symptoms and voltage readings.
12 V · Simplified two-lamp-per-side teaching model · Works offline1 · Operate the circuit
Start with a healthy circuit. Use the stalk or activate the hazard switch.
Stalk centered · Hazards off
Left front
Right front
Left rear
Right rear
Fully lit Dim / reduced voltage Open lamp
Left-side current0.00 AFront + rear
Right-side current0.00 AFront + rear
Flash frequency—When active
FuseGood10 A example
Left lamp voltage0.00 VMeasured across a good left lamp
Left ground drop0.00 VReturn to battery negative
Readings update when the flasher output is ON. If the lamps are OFF, voltage at the lamp feed may be 0 V. Turn on the appropriate side before diagnosing it.
2 · Follow the current path
Watch which branch receives power when you move the stalk or turn on hazards.
12 V battery→Fuse (good)→Flasher / control→Stalk: off→Front + rear lamps→Chassis ground
Start with a healthy left or right signal and identify the two lamps that flash together.
3 · The Challenger: diagnose the symptom
Choose a case. Observe the lamps, flash speed and meter values before answering.
Operate the left turn signal. What should happen in a healthy circuit?