Please help!! 1971 340 duster having major ignition wiring headaches.
It flows from the alternator or battery to junctions where it branches off to circuits that need it.
Engine running, current flow looks like this.
The Chrysler 4 pin ECU is powered through the light blue wire. It draws power whenever the key is in Run (or start).
So the resistor drops the voltage in proportion to current flow.
Resistance varies with temperature, current flow varies with coil and rpm so I can't give you an exact number. An osciliscope is more useful than a meter for checking coil primary voltage.
Electric current is like water flowing though a pipe.
It flows from the alternator or battery to junctions where it branches off to circuits that need it.
Engine running, current flow looks like this.
The coil negative wire is connected to ground every time the magnetic pickup signals the rotor has moved to the next spark plug.
The Chrysler 4 pin ECU is powered through the light blue wire. It draws power whenever the key is in Run (or start).
So the resistor drops the voltage in proportion to current flow.
Resistance varies with temperature, current flow varies with coil and rpm so I can't give you an exact number. An osciliscope is more useful than a meter for checking coil primary voltage.