I have a problem. When I bought my car, it had a 5" Autometer Monster tach installed in it. Recently, it stopped working properly. I ripped the dash apart and found the reason. There are four wires going from the tach to the car: red, white, black, and green. The green wire was disconnected. The red and white wires are going to the instrument panel while the black one is the ground. Does anyone know where the green one should go??? I played w/ it for a little and when I turn the key, it lights up which indicates to me that power is getting to the tach and the shift light. I can calibrate my shift point also. The tach just does not work as far as displaying the rpms while driving. Any help would be appreciated. Thanks

Before anyone says it, I am going to replace it eventually w/ a smaller 3 3/4" Phantom II tach that is a little more discrete. The Monster is huge and gets attention, both positive and negative. I just wanted to keep it working at the moment instead of running the risk of driving w/ a HUGE gauge that does not work aka ricer. Thanks!!!!

 

Red is power supply, black is ground, and white is the light for the tach, the green is what makes the Tach work, that goes to your coil.

 

Thnxs. Now, where is it located??? The wire was hidden when I found it and it just fell out. I knew it was the prob. I did see where you sometimes need an adapter to hook up a tach. Any ideas on a location???
Thnxs man and by the way that is a nasty setup you have for your stang. Very nice and good lookin. esp. w/ that 03/04 engine.

 

the Green wire goes to the Negative side of you coil. The White goes to the lights,the Red goes to the 12 Volt.and Black to Ground. Hope this helps!!

 

Alright, I am frustrated. I have tried to wire it correctly and cannot find out how. I have tried two ways already.
1. I have tried to locate where it is suppose to go or the other end of the wire. Did not work.
2. I have called Autometer. The guy told me to attach it to the 48 wire in my computer harness. It should be an orange wire w/ a white stripe. I cannot find that particular wire but about 4 wires that are orange w/ light yellow, cream, or something. I have not been successful w/ this technique either. ( I did discover that I have a diablosport computer though.)

3. Finally, where is the coil that I am suppose to attach to the negative side???? Do I have to go out through the firewall to do this??? I am sorry but this is the only gauge I have and I did not install it so I am dumb in this case. Please help me out!!!!

Thank-you for any help on any of these three techniques!!!!

 

Got it installed yesterday. I called autometer and eventually found the wire that they were telling me about. Hooked it up and it works great for now....I will replace w/ Phantom II gauges soon.