Installing Shift Light, Which is which

[92acclude]

I need to know which wire on the back of the tach is power, ground, signal.

info: 92 ex w/ H22
Shift light is a raptor performance, courtesy of Soysauce

Alternatively, can someone tell me the same wires in the harness.

[92acclude]

PLEASE

Does anyone have any ideas. I looked through my Helms/Chilton and couldn't find anything, and Soysauce didn't remember.

Help.