I'm looking for the tach wire

[oldfox]

Hi, I'm changing over to an old school blower with a carb and I would like to keep factory tach working. I will be running a Mallory distributor with a blaster coil and a MSD 6-BTM box. I'm hoping to hook in at the -side of the coil.
anyone know right off where I can pick up the tach wire? I think it runs to the negative side of the stock coil-- but not sure.
Help? Thanks

 

[Kdubslugga]

i believe its the green wire coming off the ignition coil.

 

[DonMaximo]

Yes, Negative side of coil

-OR-

You can tap into the signal which feeds your factory tach:
which would be the Dark/Green & Yellow wire for an 87-89 Mustang.
or Pin #11 (tan & yellow) on the left side cluster connector for 1990-1993

 

[HISSIN50]

If using a box, you would probably not want to tap into the neg side of the coil (multiple sparks affect the reading).

 

[Animal-Mother]

Which wire off the harness would I be hooking up to the distributor in an '83 Mustang? I recently put in an HEI style distributor and want my tach working again.