Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Ignition System: Operation
A trigger wheel turns with the distributor shaft. As each trigger wheel tooth approaches and passes the pole of the magnetic pick-up coil, the magnetic field created by the permanent magnet concentrates, strengthens and collapses. As the tooth passes the pick-up pole, the magnetic field collapses, This induces a low-voltage alternating current in the windings of the pick-up coil.
This low voltage signal passes to the control module, which makes or breaks the primary ground circuit of the ignition coil, depending upon the polarity of the pick-up coil signal. This induces a high voltage surge in the coil secondary windings that fires the spark plugs. Control module also controls the dwell angle (coil build-up time measured in distributor degrees).
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.