Ford Repair: tachometer, factory tach, tach adapter

Question
hello, i am trying to wire up a factory tach. in a 93 mustang 5.0. the car has been converted to a carberator system and has no factory wire harnis. we used a msd ignition system.the tach has 3 electrical prongs that go into the gage circuit board.do you know how to hook up this tach? we are trying to keep the factory look in the dash. thanks. kevin

Answer
Kevin-

  Carb swaps are weird like that.  Since you're not using the factory ignition control module anymore, you'll have to trick the tach.  Hopefully you've kept the wiring harness that used to be used for the factory ignition module, because you'll need it.  You'll have to cut the insulation around the harness and find the tach wire. I believe it's the green wire with a yellow tracer (basically a yellow stripe).  Cut the wire and attach it to the coil post (it's been a while, but I think it hooks to the positive side).  You'll probably need MSD's tach adapter since the factory tach won't work with an MSD ignition box.  If this stuff is now gone, you'll probably just have to hook up an aftermarket tach which isn't terribly difficult.  Hope this helps.

Steve