Gizzmo problems

[BBBrad]

I got the car running and all is good. Having alot of trouble with the gizzmo shift light and launch control. Got the problem down to the shift light. The tach signal wont go through (wired in series) to the tacho. The wiring is all top notch and the tach will run fine when not wired through the shift light. Have been told the signal needs to be a grunty clean signal and I may have had to have a booster installed to help. So now I have my signal coming straight from the coil negs, about the gruntiest you can get.
Anyone had any problems like this? Had to send any gizzmo products back?

[Caveman]

Method on these forums went through 3 launch controllers. All faulty and replaced free of charge by gizmo in auckland. They installed them too.