MOPAR Performance Ignition "MSD" tach Qustion...

[Woodie]

A quick qustion in regards to the Mopar Performance digital ignition system PN#4876728 (MSD 6AL) and the use of a vintage Sun Super tach. I have the original wiring diagram that came with the tach. The MSD ignition has the provision for a tach hook-up on the side. Has anyone here used a vintage tach with this ignition? The instalation instructions say the tach output on the controler produces a "12volt square wave signal" is the same signal as the use of "old school negitive side of the coil"? Any help would be greatly appreciated!

Woodie.

 

[dogbreath]

run the green tach wire to the msd tach output , should work fine

 

[66340SEDAN]

I have a 6AL in my car and after I installed it my vintage Sun tach wouldn't work, the higher it would rev, the lower the rpms on the tach read. Maybe need a MSD splitter? I pulled the tach and replaced it with a early vintage Auto Meter one and it works great! Both tachs had the green wire hooked up to the MSD box.

 

[Woodie]

Voltage Triggered: If the trigger wire of the tach was originally connected to the coil negative terminal you have a Voltage triggered tachometer.
Current Triggered: If the trigger wire of the tach was originally connected to the coil positive terminal, it is a Current Triggered Tachometer.
Wiring with...

... This explains it,