Shantymac

Where is the electronic ignition box that we hook the tach up to on the 88 mustang.

mustangdave357

Not exactly sure what you mean, there should be 4 wires. Red is hot with the key, white is hot with parking lights/ headlights. Black is ground and green goes to the - side of the coil, Dave

VertStangGT86

The stock TFI module is on the distributor, it's the gray box that has a wire harness coming out of it. That's probably where you hook it up.

nhdungeonracer

Actually, for that year you splice into one of the wires coming from the coil. Pretty sure it's the wire closest to the fender looking down at the coil.

roundman

sorry about this guys, but you're all wrong except mustangdave.
you splice into the wire at the coil nearest the motor, not nearest the fender. on my 88 this wire is red with a blue stripe if I remember correctly. hope you don't have the same problem I had with mine, it wouldn't work right and I called Autometer and they suggested I use a piece of coax cable instead of the green wire for the tach pick-up and I did this and it still wouldn't work right, so I pulled it off last week and sent it back and am waiting for them to fix it and return it soon. if you have an aftermarket ignition like an MSD, don't hook it up to the stock coil, hook it up to the tach outlet on the MSD box or you'll ruin the tach from the higher voltage the aftermarket box puts out to the coil.

WesDe

Roundman what do you mean did not work right. Mine works but is about 500 rpm lower than the stock on the dash. I heard that the stock tachs are not that accurate. i hope im not overreving the engine.

roundman

when I first installed mine, it would go only to about 3,000 rpm then drop back down to zero and bounce around then stay there. after I used the coax cable, it would go to about 5,000 rpm, then do the same thing dropping off and bouncing around. so I pulled it off and sent it back to them. I would not worry about the difference in the readings between the two as 500 rpm ain't enough to get excited about.

VertStangGT86

That's not bad from what other poeple have said about theirs being off. Other poeple on here have been off a hell of a lot more then that.