Shift Light on WRX

[sixworks]

A friend has just fitted a shift light to his WRX and it doesn't work. I haven't had the opportunity to check his install but I seem to recall a similiar thread some time ago with someone having the same problem.

I suspect the problem may be due to the low voltage ECU tacho output but, as I said, I haven't had the chance to look at it yet.

I've never delt with shift lights myself but I'm sure many others on this forum have. Has anyone had the same experience and if so, what was the solution?

Thanks,

Grant