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65 Fastback, 351W, MSD Ignition, car has been completely rewired.

Ok, trying to get a factory rally pack tach to work with my MSD ignition (6AL Ignition box, blaster 2 coil). I no longer have the pink resistor wire in my system. Car has been rewired.

When I first got the Rally Pac, I wired it in ignorantly like it was a modern tach, red wire to neg of coil and black wire to ignition switch. It worked, but the wiring got really hot really fast. I shut everything down, did my research and wired it to the positive post of the coil as it would have originally been done. To the positive post, my car cranks but wont start. When cranking tach registers about 600 rpms. Figured I was basically shorting out my ignition system (why it wouldnt start). Did additional research, found out I should wire to the ignition box.

When wired to MSD box, I would get about 500 RPMS when started, but nothing more.

Further research, found out Id likely need MSD 8920 tach adapter and a ballast resistor between ignition switch and tach.

Got the parts, wired it in and now I get nothing.

Any thoughts, did I fry the tach, is there a way to test it?

Also, on the ballast resister, I am wiring between tach and ignition switch. When checking voltage, the voltage coming out of the ballast resister is still 12+/- volts. Shouldn't I see a voltage drop?

Just for checking I wired it back to the positive post and when cranking the needle moves.
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