Key on wire for MSD ignition and one wire alt
The one your missing goes from starter relay,marked ign,to msd red wire also.
NEGATIVE. No wire goes to the starter relay
On ALL these Mopars there are only TWO wires which supply underhood ignition loads. This includes ignition, voltage regulator, alternator field, electric clutch if used, and idle solenoid if used, as well as "smog doo dads" on some years.
These are the "ignition run" IGN1 wire, some years (but not all) is DARK BLUE. This feeds the "jumpered" wires of your 4 pin ballast, the alternator field (blue) and the blue VR wire
BUT THIS WIRE GOES COLD during cranking.
The SECOND wire is BROWN, IGN2, and this "used to" go to the coil + side of the ballast. THIS IS THE ONLY source of ignition during "cranking."
You must jumper those two together, and hook them to the MSD small red.
