Help wiring OEM SW Tack to MSD Dist

Clois Harlan · #1 (**permalink**) 12-14-2004, 01:03 PM

I have an orig tack that s/b wired to the neg side of coil that I need to connect to my MSD dist. Orig tach oper on single spark technology where as MSD is multi spark circuit. How do I wire this up where tach gives reliable reading at all ranges?

Clois

CSCHWER · #2 (**permalink**) 12-14-2004, 02:42 PM

Does you MSD unit have a tach output? If so, try that first. MSD make a tach adapter that you may need. Don't use the coil neg. terminal! Really need to know what MSD box your using.

Hotfingrs · #3 (**permalink**) 12-14-2004, 02:52 PM

Don't have an MSD manual in front of me, but I believe the green wire is the tach wire. Mine is wired directly to my gauge.

Clois Harlan · #4 (**permalink**) 12-14-2004, 03:40 PM

The issue here is that my friend is using an original 67 Mustang Stewart Warner Tachometer with a new age multi spark distributor. He has been told that if he just wires the tach to the tach wire he could "fry" his highly valued original equipment gauge. This is an original 67 Mustang 427 S.O., 4 speed car originally owned by one of the Vice Presidents of Ford, It is a "one of" car with less than 40,000 miles. After 34 years of storage he intends to upgrade some of the components along with a complete "body off" so to speak restoration he is completing.

I know this sounds strange but he say's that the ignition wire that starts the car also feeds back to the tach and provides the signal for the tachometer. Has anyone delt with this before?

Thanks in advance for your input.

Clois