thunderbolt switch box wiring? brown wire?

[billgabbert1]

i'm ordering a cdi 114-2986 kit for my 67 merc 500. and was wondering what the brown wire on the starboard side of the box (side if 4 terminals)does?
i also had a question on step 7 on http://www.stemtostern.com/content/rainboat/CDI/114-2986.pdf
7. Reconnect the Brown wire to one of the rectifier AC terminals (Yellow wire).? i thought that the two yellow wires from the rectifier are connected there?
thanks for helping
bill

 

[Moody Blue]

Re: thunderbolt switch box wiring? brown wire?

The brown wire is the tach signal wire that runs up to the MerControl unit. The older style Merc tachs took the signal from the CDI switchbox. The newer tachs require a different signal source and it is necessary to change the location of the brown wire from the CDI box to either one of the rectifier terminals.