39 4 wire ignition coil diagram
The trigger signal rises from 0 V to about 4 V at coil switch-on and then returns to 0 V at coil switch-off. The time between these events is the dwell period or coil saturation time, determined by the Engine Control Module (ECM) or ignition amplifier. Channel B. Feedback signal. The feedback signal tells the ECM that ignition has occurred. What do the letters mean on the back of an ignition switch? “R” is typically to indicate “red wire” out to components that need 12V power in the RUN position of switch (Cub to name one). “S” indicates starter control out. “L” can indicate lights if lights function is part of the key switch duties (may have other functions on different machines. Apr 27, 2011 · IGNITION COIL TEST 3: Verifying Ignition Coil Is Getting 12 Volts So far, you have verified that you do have a bonafide no spark situation coming directly from the ignition coil because: One: Your Ford's no-start condition is due to a lack of spark (and nothing else). Two: You hav...