Stock Tach not working but other gauges do

[Gooberlog]

My car is now runing after the engine rebuild but the tach is not functioning at all. The factory "boost" gauge is working and so are the other gauges but no tach output, it doesn't move at all. Did they forget to plug something in? Thanks
Gooberlog

 

[ILOSE]

There is a small metal box with two wires coming out of it. It is goldish and is maybe an inch long and 3/8" high. There is a mitsu symbol on it and there is a niine digit number on it as well. I have no idea what the name of it is. But it MUST be grounded! there is a flange for a 10mm bolt to go through it. You can find it around the intake manifold area. More to the timing belt side.

 

[Gooberlog]

So there is a grond wire that comes out of the small goldish box? Where is this box located? Thanks so much for the reply.
Travis

 

[ILOSE]

The box has 2 wires going into it. But you don't ground a wire. When you put a bolt through the hole in the flange it grounds the unit. You can search area behind the manifold. Look around the the coil pack also it may be mounted on there. or check the firewall. I am not sure where it went from the factory as mine has been moved for a long time. I just know that without that thing the tach will not work. I'll see if I can scroung up a pic for ya somewhere.

 

[Gooberlog]

THanks i really appriciate it, so out of the two wires, does one of them have to be grounded or both not. Thank you.
Travis