Installing MSD6AL
WHAT YEAR MODEL car are we working on?
Two of the wires are jumpered together, you can see the blue jumper at the one end
That is your "run" line. One of the other two goes to coil + and the other goes to the ECU which is not needed.
Find a wiring diagram, leave the wire going to the box loose, and jumper the other two together.
Now take your coil+ wire and use that to feed the "small red" of the MSD, which is an arming, or trigger wire
MAKE CERTAIN that you do NOT have ANYTHING connected to the coil except for the two coming from the MSD. No tach, no radio capacitor, nothing else.
Read up on your tach and the MSD as to what to do for your tach connection