⚡ TESTING GM 4-Pin HEI Ignition Module, both on the bench and in the car. If your engine’s cranking but won’t fire — this is the first thing you should check. ✅ Power ✅ Ground ✅ Coil Negative Switching If it ain’t switching — it ain’t sparking. #IgnitionTrouble #NoSpark #HEIModule #GMTech #CarWontStart #DiagnosticsDoneRight Part 17 | My Mobile Mechanic / Auto Repair & Brake Replacement.

For more automotive training, sign up for ScannerDanner Premium https://www.scannerdanner.com/join-scannerdanner-premium.html The cost is $11 a month giving you access to over 420 training videos and counting. Tests shown - how to use GM misfire data during diagnostics - understanding ignition coil control circuit design - ignition module transistor operation and testing - how to scope test an ignition module with voltage and current - how to test an ignition module with a test light - how to oh