BTM...no more tach?

[The Viz]

Hey guys, I'm sure this is gonna be an easy answer, but I'm lost. I installed an MSD BTM on my sister's '94 LS with a Rev-Hard kit, and now the tach doesn't work. I saw somewhere that the BTM modifies the signal for the negative side of the coil, and that causes the tach not to work. It said something about jumping the tach sense wire to coil, but even w/ a Haynes manual I'm a bit lost.

[lowpatrol]

the btm has an output for the tack just jumpit to that. i also have a btm but factory tach still works

[The Viz]

Originally posted by lowpatrol
the btm has an output for the tack just jumpit to that. i also have a btm but factory tach still works

The instructions suck with this thing, but I do know that no where in the instructions does it say that there is an output for tach. It's just a BTM, not an ignition with built in BTM. Anyone have any input on this.