Yes and no. I made up my own loom taken from each side of the coilpack using a couple of diodes and wired it directly to the rev counter. Started the engine and it worked spot on, then after about 30secs it started fluctuating and then stopped. Took the clocks out and plugged it into my other sierra and the rev counter works fine. I compared all the connections from car to car and the only difference is that at idle the voltage on the rev counter trigger is 10V in my sierra running standard coil, but at idle in the cosworth its 16V. Not too sure if this is making something on the gauge cut out after a few seconds due to to much voltage? Because the rev counter works when I start the engine everytime then stops. Its a nightmare!!