I have a Autometer Tach and the adapter #9117 I'm wiring in my 98 Camaro. The Autometer instruction call for the adapter to be connected to the pink wires in the engine harness for 12 volt power and coil power. 99-02 car all have IPC class 2 serial data wire that sends the signal for all gauges from the PCM to the gauge cluster in a single wire. On a 98 it is an analog signal so the tach has its own separate wire coming from the PCM. Any reason I can't hook the adapter to the tach wire coming from the PCM instead of cutting into the engine harness and then get power to the adapter and tach from a 12 volt ignition wire?