MSD 6al box installed w/o tic toc tac hooked up but tac still bouncing ? ? ? ? ?

[skip68]

     I just put in the msd 6al box and all seems good but my tic toc tac is bouncing all over the place.       What the hell is going on ? ? ? ? ?    The wire from the Tac to the negative side of the coil is NOT hooked up.   I left it disconnected until I get the tac adapter but for some reason it seems to be bouncing all over.    Any ideas ?      Thanks,  Chuck..................

[Houston-Toe-Cutter]

Hi. I just bought a MSD 6AL to install in my 69 charger. How did you do it? Do you have to remove the heater box to install it on the firewall? pix please

[Ghoste]

It isn't hooked up?  Sounds like electrical demons to me.

[skip68]

I put it on the drivers side by the fender tag.  There was some bad wires at the bulkhead.   

[John_Kunkel]

EMI? Try wrapping the end of the tach wire in aluminum foil.

[Houston-Toe-Cutter]

I put it on the drivers side by the fender tag.  There was some bad wires at the bulkhead.   

I just finished installing mines on the firewall. Took the heater box out. It was eazy for me but did have to take a lot of other stuff out to do it.

[Jaysick]

I had to install a filter to keep my Autometer tac from bouncing.
http://www.summitracing.com/parts/msd-8830