HELP, What is this wiire on my Faria multi-function tach?

[pvett]

I have a Larson Senza 206. I have a Faria Multi-function Tachometer. My tach is not working. When I turn the ignition switch, it doesn't jump, so I assume it's not getting power. The picture is of a wire that is attached to the power terminal. Already attached to the power terminal is a purple wire (power) so I'm not sure what this wire does. Right now this wire is not attached to anything else but the tach. I assume this is my problem. Does anyone know what this should plug into?
thanks,
Phil

 

[Bill kubiak]

Re: HELP, What is this wiire on my Faria multi-function tach?

I just installed a new faria tach in my boat. I cannot tell you anything from that picture
Purple wire to pwr
Black wire to ground
Grey wire to signal

 

[pvett]

Re: HELP, What is this wiire on my Faria multi-function tach?

yea, i'm not sure what the second wire is for? It comes off of the terminal red, goes into this red plastic fuse box looking thingy, then a wire comes off of that black and goes into nothing... Anyone else have any ideas?