You most likely only had the tach signal wire. That one has the power and ground for the instruments as well. Along with two wires for a bow mounted tilt switch for the motor. (in case you have a bass boat) You only need to use the gray wire.
Do you have power tilt and trim?
Some folks like the thumb-switch on the control. Personally, I like a separate switch (preferably an (on)-off-(on) toggle) for PT&T; the switches they put in those controls (and the wiring coiled around inside the control) can be a major weak point in my experience (shorts from wiring insulation damage or water intrusion in the switch).
You can use something like this one http://www.iboats.com/SeaStar-Unive...37465099--**********.872822351--view_id.40282 but you will need new cables and you would need to adapt the wiring.