This is going to sound real dumb but maybe i'm just clueless. My 94 DX didn't come with a tach so obviously I am putting one in, I know how to hook it up except for this freaking green wire which is supposed to go to the negative side of my ignition coil/ Tach test/ ecu terminal. If you have advice or know where the heck to hook this thing up I would be very appreciative.

 

Dont know which ECU pin (if any), off the top of my head.
You could just snake the green wire all the way to the dizzy, pop off the cover and locate the - coil wire.

Cmon, someone here had got to know wich ECU pin to use, Im way to lazy to look right now.....beer and vike's rule!!!

 

this is a easier way....run that wire through the fire wall on the driver side. then on the driver side corner of the wall, you'll find the endplugs of your wiring harness. now next to that will be a blue (i think) wire that has a plug on it but is connected to nothing. just in a rubber cover. if it has never been tampered with...it'll be wrapped up in stock tape. unwrap that and tap into it and it'll give you the coil signal. always worked for me.

 

on 4g civics there is a tach wire on the plug that goes into the gauge cluster, it's blue, that's what I taped for my tach on my dx, no fire wall ------- with required.

 

thats all, tap the green wire to the blue wire located on the distributor plugs. easy as that no I couldnt figure that damn thing out for a couple days.