aftemarket Tach help needed

[mark268]

Installing an aftermarket Sunpro tach into my 1987 xj 4.0 auto. What wire do I hook the "green" tach wire to? Said something about the negative side of coil...... what color is this wire? HELP

 

[BrettM]

I put one on my 88 4.0 in the XJ I used to have, I don't remember well enough to tell you exactly, but if you find a good wiring diagram is shows the place. it was on a little wiring harness with I think 3 wires connected to the coil.