[TonyMadrid]

If you're using the SW gauges that came with the A&C Kit you have to make sure that you have the Tach wired correctly. I am using an MSD 6AL Ignition Control Unit and the p/w that came with the unit indicates that you might need an adaptor for a SW Tach. I called MSD and their tech wrongfully told me to just follow the Tach Manufacturers instructions for wiring it up. Well, according to the SW p/w it says to wire the Tach SIG (signal) terminal to the negative terminal of the coil. I did that but no good, won't work. I called SW and they told me to wire the SIG terminal to the MSD Ignition Control Unit. Did that and "bingo", got tach.

On the side of the Ign Control Unit there is a connection for a plug in wire that comes with the unit. Attach that wire to the SIG terminal of the tach and plug it in to the Ign Cont Unit and tach should work.

You mention that you have an MSD 6AS; I am not familiar with that unit and I couldn't find it in Summit but I would think it has the same connection arrangement.

Good Luck,

Tony