All Small Six Msd tach adapter

This relates to all small sixes

beanmiester

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So i have the tach wired slightly different bypassing the resistor wire but based on these diagrams. How should I wire the msd adapter to the tach that way it will work with the dui?
 

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It looks like your tac needs a signal that is reduced by a resistor and full 12v power supply. ( from looking at the tac diagram). So on the MSD diagram a ballast resistor needs to be added between the box / trigger wire- red- and your tac. The only glitch with that is I don’t know what the MSD tac adapter out put is. The safe thing would be to call MSD tech and tell them your tac needs a resistor inline for reduced voltage and see what they say
 
I got it to work. I don't know how accurate it is yet but its registering and only lags behind the rpm increase slightly
 
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How the msd diagram wanted it. I took the wire i originally had going to the tach output on the dui and split it so I could just plug the box into the wiring I already had done. I also found out that I had the 12v power and trigger wire reversed originally. Oops. In my defense both plugs are black on the tach harness for some dumb reason. It still wouldn't have worked anyways because the dui doesn't put out a signal it can understand so 🤷‍♂️.
 
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