[Blue91hatch]

So I bought a shell that had no instrument cluster in it and I decided to make my own, I've got the car done and running and driving but have no tach, I bought an iequus tach from O'Reillys, I also installed the autometer tach adapter that I read you have to run and when I installed it the car wouldn't start anymore, I ran it in series with the blue/red wire leading to the coil pack subharness, I undid the splice and it fired right up, so I tried wiring it to the yellow/red wire from the ecu and it still wouldn't work, then tried wiring it to the ground side of one of the coils (that's what the tach instructions said to do for a c.o.p. car) and it still didn't work, there's a drift event tomorrow morning I'm trying to go to but would really like a tach, does anyone have any ideas? Thanks in advance!!